COMPOSITION OF AND TREATMENT WITH BIOLOGICALLY ACTIVE PEPTIDES HAVING D-AMINO ACID RESIDUES

Abstract: A biologically active peptide wherein each amino acid residue of the peptide is a D-amino acid residue or a glycine residue. Examples of such peptides wherein each amino acid residue is a D-amino acid residue or a glycine residue include deletion and substitution analogues of magainin peptides, CPF peptides, PGLa peptides, XPF peptide, and derivatives of cholecystokinin. Such peptides have increased resistance to proteolytic enzymes while retaining bilogical acitivity.

Description: COMPOSITIONS OF AND TREATMENT WITH BIOLOGICALLY ACTIVE PEPTIDES HAVING D-AMINO ACID RESIDUES This invention relates to biologically active peptides, and more particularly to biologically active peptides wherein each amino acid residue of such peptides is a D-amino acid residue or glycine. In accordance with an aspect of the present invention, there is provided a compound comprising an analogue of Magainin I Peptide or Magainin II peptide. Each amino acid residue of the Magainin I peptide and the Magainin II peptide is a D-amino acid residue or glycine. The Magainin I or Magainin II peptide is in an amide or carboxy terminated form. Magainin I is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residues refer to the position of the residue in the peptide. G I G K F L H S A G K F G K A F V G E I M K S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Magainin II is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A K K F G K A F V G E I M N S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 The Magainin I or Magainin II peptide is substituted in at least one of positions 1-23. The substituents which may be employed in each of positions 1-23 are shown in the following table: Residue No. Substituent 1 D-Lys,D-Ala 2 D-Lys,D-Ala, D-Ile,D-Arg,D-Leu,D-Val,D-His,D-Met 3 D-Lys,D-Ala,D-Trp,D-Arg,D-His 4 D-Lys,D-Ala,D-Arg,D-His 5 D-Phe,D-Ala,D-Lys,D-Trp,D-Le ,D-Ile,D-Val,D-Met 6 D-Leu,D-Lys,D-Ala,D-He,D-Val,D-Met 7 D-Lys , D-His , D-Ala, D-Arg, D- I le , D-Val , D-Met 8 D-Ala , D-Lys , D-Ser , D-Trp , D-Met , D- 1 le , D-Arg, D-Hi s , D-Thr , D-Leu , D-Val 9 D-Lys , D-Ala , D-Trp , D-Arg, D-Hi s , D-Leu , D- 1 le , D-Val 10 D-Lys D-Ala, D-Trp, D-Arg, D-His , D-Leu, D- He, D-Val 11 D-Lys , D-Arg, D-His 12 D-Phe, D-Lys, D-Trp, D-Arg, D-His 13 D-Ala , D-Lys , D-Trp , D-Met , D-Arg , D-Hi s , D-Phe , D-Leu , D- He, D-Val 14 D-Ala, D-Lys, D-Arg, D-Hi s 15 D-Lys, D-Trp, D-Ala, D-Arg, D-His, D-Phe 16 D-Ala, D-Lys, D-Phe, D- He, D-Val , D-Met, D-Leu 17 D-Ala, D-Lys , D-Val , D-Trp , D-Arg, D-His , D-Met , D-Leu 18 D-Ala, D-Lys , D-Trp , D-Arg, D-Hi s , D-Leu , D-Met 19 D-Ala, D-Lys , D-Glu, Gly, D-Arg, D-His, D-Leu D- I le , D-Phe , D-Asn 20 D- I le , D-Ala, D-Lys , D-Trp , D-Le , D-Phe , D-Val , D-Met 21 D-Lys , D-Pro , D-Ala , D-Hi s , D-Leu , D-Arg, D- 1 le , D-Phe 22 D-Lys ,.D- Ala, D-Asn, D-Gln, D-Arg, D-His 23 D-Ser,D-Lys,D-Ala,D-Thr,Gly,D-Leu,D-Ile, D-Gln,D-Asn Preferably, the substituents are as follows: Residue No. Substituent 1 D-Lys,D-Ala 2 D-Lys,D-Ala,D-Ile 3 D-Lys,D-Ala,D-Trp 4 D-Lys,D-Ala 5 D-Phe,D-Ala,D-Lys,D-Trp 6 D-Leu,D-Lys,D-Ala 7 D-Lys,D-His,D-Ala 8 D-Ala,D-Lys,D-Ser,D-Trp 9 D-Lys,D-Ala,D-Trp 10 D-Lys D-Ala,D-Trp 11 D-Lys 12 D-Phe,D-Lys,D-Trp 13 D-Ala,D-Lys,D-Trp 14 D-Ala,D-Lys 15 D-Lys,D-Trp,D-Ala 16 D-Ala,D-Lys,D-Phe 17 D-Ala,D-Lys,D-Val,D-Trp 18 D-Ala,D-Lys,D-Trp 19 D-Ala,D-Lys,D-Glu 20 D-He,D-Ala,D-Lys,D-Trp 21 D-Lys,D-Pro,D-Ala 22 D-Lys,D-Ala,D-Asn 23 D-Ser,D-Lys,D-Ala It is to be understood that for purposes of the present invention, that the D-tryptophan residues may be protected with a formyl group or be unprotected. The D-phenylalanine residues, whether such residue is present in its normal position, or employed as a substitution residue, may be a normal D-phenylalanine residue or an iodinated D-phenylalanine residue. - - In accordance with one embodiment, the peptide is a Magainin I peptide, and at least one of amino acid residues 8, 10, 13, 16, 18 and 19 is substituted with a D-alanine residue. In another embodiment, the Magainin I peptide has D-alanine residue substitutions at each of amino acid residues 3, 8, 16, 19 and 23. In accordance with another embodiment, the Magainin I peptide has D-alanine residue substitutions at four of amino acid residues 3, 8, 16, 19 and 23, and the remaining one of these residues is substituted with a D-lysine residue. In accordance with yet a further embodiment, amino acid 21 of a Magainin I peptide is substituted with a D-proline residue. In accordance with another embodiment, at least one of amino acid residues 3, 7, 8, 10, 18-21, and 23 of Magainin I is substituted with a D-lysine residue. In accordance with another embodiment, amino acid residues 3, 8, 9, 19 and 23 of Magainin I are each substituted with a D-lysine residue and amino acid residue 16 is substituted with a D-alanine residue. In accordance with a further embodiment, at least one of amino acid residues 3, 5, 8, 10, 12, 13, 15, 18, and 20 of Magainin I is substituted with a protected D-tryptophan residue, wherein the protecting group is preferably a formyl group. In accordance with another embodiment, at least one of amino acid residues 9, 13, 15 and 17 of Magainin I is substituted with an unprotected D-tryptophan residue. In accordance with another embodiment, the peptide is a Magainin II peptide, and at least one of amino acid residues 1-8, 10, 13, 14, 16 and 18-23 is a D-alanine residue. In accordance with another embodiment, at least one of amino acid residues 1-3, 5-9, 12, 13 and 15-23 of Magainin II is a D-lysine residue. In accordance with another aspect of the present invention, there is provided an analogue of Magainin I or Magainin II peptide, said Magainin I or Magainin II peptide being in an amide- or carboxy-terminated form and having the structural formulas hereinabove described, wherein each amino acid residue of said Magainin I or Magainin II peptide is a D-amino acid residue or glycine, and wherein at least one of amino acid residues 15-23 is omitted and at least one of the remaining amino acid residues is substituted. The substituents which may be employed in at least one of positions 1-23 are shown in the following table: Residue No. Substituent 1 D-Lys , D-Ala 2 D-Lys , D-Ala, D- He, D-Arg, D-Leu, D-Val , D-His, D-Met 3 D-Lys , D-Ala, D-Trp, D-Arg, D-His 4 D-Lys,D-Ala, D-Arg, D-His 5 D-Phe, D-Ala, D-Lys , D-Trp, D-Leu, D- He, D-Val , D-Met 6 D-Leu, D-Lys , D-Ala , D- I le , D-Val , D-Met 7 D-Lys , D-Hi s , D-Ala , D-Arg, D- 1 le , D-Val , D-Met 8 D-Ala, D-Lys , D-Ser, D-Trp, D-Met, D- He, D-Arg, D-His, D-Thr, D-Leu, D-Val 9 D-Lys , D-Ala , D-Trp , D-Arg, D-Hi s , D-Leu , D- 1 le , D-Val 10 D-Lys, D-Ala, D-Trp , D-Arg , D-Hi s , D-Leu , D- He , D-Val 11 D-Lys, D-Arg, D-His 12 D-Phe , D-Lys , D-Trp, D-Arg, D-His 13 D-Ala,D-Lys,D-Trp-,D-Met,D-Arg,D-His,D-Phe, D-Leu,D-He,D-Val 14 D-Ala,D-Lys,D-Arg,D-His 15 D-Lys , D-Trp , D-Ala , D-Arg, D-His , D-Phe 16 D-Ala , D-Lys , D-Phe , D- He , D-Val , D-Met , D-Leu 17 D-Ala, D-Lys , D-Val , D-Trp , D-Arg, D-His , D-Met , D-Leu 18 D-Ala , D-Lys , D-Trp , D-Arg, D-Hi s , D-Leu , D-Met , D-Phe 19 D-Ala, D-Lys , D-Gl , Gly, D-Arg, D-His , D-Leu, D- He , D-Phe , D-Asn 20 D- I le , D-Ala , D-Lys , D-Trp , D-Leu , D-Phe , D-Val , D-Met 21 D-Lys , D-Pro , D-Ala , D-Hi s , D-Leu , D-Arg, D- 1 le , D-Phe 22 D-Lys , D-Ala, D-Asn, D-Gln, D-Arg, D-His 23 D-Ser, D-Lys, D-Ala, D-Thr, Gly, D-Leu, D- He , D-Gln, D-Asn Preferably, the substituents are as follows: In accordance with a particular embodiment, amino acid residues 16-23 of Magainin I are deleted, and amino acid residues 3, 8 and 10 are substituted with a D-alanine residue. In accordance with yet another embodiment, amino acid residue 19 of Magainin I is deleted, and preferably amino acid residues 5, 8, 9 and 16 are each substituted with a D-lysine residue, amino acid residue 21 is substituted with a D-leucine residue, and amino acid residues 18 and 23 are substituted with a D-alanine residue. In accordance with another embodiment, in carboxy- or amide-terminated (preferably amide-terminated) Magainin I or Magainin II peptide, amino acid residues 17-23 or 16-23 or 15-23 are deleted, and amino acid residues 3, 7, and 8 are each substituted with a D-lysine residue, and optionally amino acid residue 13 and/or amino acid residue 10 is substituted with a D-alanine residue. Preferred peptides are as follows: GIKKFLKKAGKFGK-NH 2 GIKKFLKKAGKFGKAF-NH 2 GIKKFLKKAKKFGKA-NH 2 GI KFLKKAKKFAKA-NH 2 GIKKFLKKAAKFAKA-NH 2 Preliminary studies indicate that the above-mentioned preferred peptides possess low hemolytic activity. In accordance with a further embodiment, amino acid residue 21 of Magainin I may be deleted, and preferably amino acid residues 5,10, 18, and 19 are each substituted with a D-lysine residue, amino acid residue 7 is substituted with a D-phenylalanine residue, and amino acid residue 22 is substituted with a D-alanine residue. In accordance with another embodiment, in carboxy or amide terminated (preferably amide terminated) Magainin I or Magainin II (preferably Magainin II), amino acid residue 19 is omitted, and at least one of amino acid residues 3, 7, 8, 10, 13, 15, 16, 18 21, 22 or 23 is substituted with another amino acid as follows: Residue number Substituent 3 D-Leu 7 D-Lys 8 D-Lys, D-Ala 10 D-Ala, D-Lys 13 D-Trp, D-Leu, D-Phe, D-Ala 15 D-Phe In a preferred embodiment, the peptide is a Magainin II peptide, and the substitution analogue wherein amino acid 19 is deleted is selected from the class consisting of the following substitution analogues: GIGKFLHSAKKFGKAFVGIMKS; GIGKFLHSAKKFGKAFVAIMKS; GIGKFLHSAKKFFKAFVFIMNS; GIGKFLKSAKKFGKAFVFIM S; GIGKFLHKAKKFAKAFVFIMNS; GIGKFLKSAKKFAKAFVFIMNS; GIGKFLHKAKKFAKAFVFI NK . GIGKFLKKAKKFGKAFVFIMKK; and GIGKFLHSAKKFGKAFVK**IMNS; wherein K** is E-F-moc-lysine. Preliminary studies indicate that these preferred analogues possess low hemolytic activity. In accordance with another embodiment, there are provided derivatives of Magainin I or Magainin II (carboxy- or amide-terminated) , preferably Magainin II, wherein a portion of the basic peptide is deleted and at least one of the remaining amino acid residues is substituted as hereinabove described; in particular, amino acid residue 19 is omitted and in addition either amino acid residues 1-4 or 3,5, and 6 are omitted. Preferred peptides are as follows: FLHSAKKFGKAFVFIMNS GI HSAKKFAKAFKAIMNS FLKSAKKFGKAFVGIMNS FLKSAKKFAKAFVGI NS In accordance with another aspect of the present invention, there is provided a compound comprising a peptide deletion analogue of an amide or carboxy terminated Magainin I, wherein Magainin I is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A G K F G K A F V G E I K S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 and wherein each amino acid residue is a D-amino acid residue or a glycine residue, and at least one of amino acid residues 15 through 23 is omitted. In a preferred embodiment, at least one of amino acid residues 15, 16, 18, 19, 21, 22 and 23 is omitted. In one embodiment, at least amino acid residue 18 is omitted whereas in another embodiment, at least amino acid residue 19 is omitted, and in yet another embodiment at least amino acid residue 21 is omitted. In preferred embodiments, only one of amino acid residues 18, 19, and 21, respectively, is omitted. In other preferred embodiments, amino acid residues 21, 22, and 23 are omitted, amino acid residues 19 through 23 are omitted, amino acid residues 18 through 23 are omitted, and amino acid residues 17 through 23 are omitted. The compound can be a deletion analogue of amide - or carboxy-terminated Magainin I . In accordance with another aspect of the present invention, there is provided a compound comprising a peptide that is a deletion analogue of an amide - or carboxy-terminated Magainin II, wherein Magainin II is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A K K F G K A F V G E I M N S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23, wherein each amino acid residue is a D-amino acid residue or glycine, and at least one of amino acids 15 through 22 is omitted. In a preferred embodiment, at least one of amino acids 15, 18, 19, 20, 21, and 22 is omitted. In one embodiment, at least amino acid 18 is omitted. In another embodiment, at least amino acid 19 is omitted. Another embodiment omits at least amino acid 21, and yet other embodiment omits at least amino acid 22. In preferred embodiments, only one of amino acids 18, 19, 21, and 22, respectively, is omitted. The compound can be a deletion analogue of amide-terminated Magainin II. In accordance with yet another aspect of the present invention, there is provided a basic (positively charged) polypeptide having at least sixteen amino acids wherein the polypeptide includes at least eight hydrophobic amino acids and at least eight hydrophilic amino acids. Each of the amino acid residues of the polypeptide is a D-amino acid residue or a glycine residue. Still more particularly, the hydrophobic amino acids are in groups of two adjacent amino acids wherein the amino acids are D-amino acids or glycine, and each group of two hydrophobic amino acids- is spaced from another group of two hydrophobic amino acids by at least one D-amino acid other than a hydrophobic amino acid (preferably at least two D-amino acids) and generally by no greater than four D-amino acids, and the D-amino acids between pairs of hydrophobic amino acids may or may not be hydrophilic. The hydrophilic amino acids are generally also in groups of two adjacent D-amino acids in which at least one of the two D-amino acids is a basic hydrophilic amino acid, with such groups of two hydrophilic D-amino acids being spaced from each other by at least one amino acid, other than a hydrophilic D-amino acid, wherein each of said at least one amino acid(s) is a D-amino acid or glycine (preferably at least two amino acids) and generally no greater than four amino acids, and the amino acids between pairs of hydrophilic D-amino acids may or may not be hydrophobic. In accordance with a particularly preferred embodiment, the polypeptide comprises a chain of at least four groups of amino acids wherein each amino acid is a D-amino acid or glycine, with each group consisting of four amino acids wherein each of the at least four amino acids is a D-amino acid or glycine. Two of the four amino acids in each group are hydrophobic amino acids, and two of the four amino acids in each group are hydrophilic, with at least one of the hydrophilic amino acids in each group being a basic hydrophilic amino acid and the other being a basic or neutral hydrophilic amino acid. The hydrophobic amino acids may be selected from the class consisting of D-Ala, D-Cys, D-Phe, D-Ile, D-Leu, D-Met, D-Val, D-Trp, D-Tyr, and Gly. The neutral hydrophilic D-amino acids may be selected from the class consisting of D-Ser, D-Asn, D-Gln, and D-Thr. The basic hydrophilic D-amino acids may be selected from the class consisting of D-Lys, D-Arg, and D-His, and D-ornithine. Each of the groups of four amino acids may be of the sequence ABCD, BCDA, CDAB, or DABC, wherein A and B are each hydrophobic amino acids and may be the same or different, one of C or D is a basic hydrophilic amino acid, and the other of C or D is a basic or neutral hydrophilic amino acid and may be the same or different. In a preferred embodiment, the polypeptide chain may comprise 5 or 6 groups of this sequence. In each group, each of A, B, C and D may be the same in some or all of the groups or may be different in some or all of the groups. The polypeptide chain preferably has at least 20 amino acids, and no greater than 50 amino acids wherein each amino acid is a D-amino acid or glycine. It is to be understood, however, that the polypeptide does not have to consist entirely of the groups described above. The polypeptide may have amino acids extending from either or both ends of the noted groups forming the polypeptide chain and/or there may be amino acids between one or more of the at least four groups and still remain within the scope of the invention, provided that each amino acid residue of the polypeptide chain is a D-amino acid residue or glycine. The groups of amino acids may be repeating groups of amino acids, or the amino acids in the various groups may vary provided that in each group of the at least four groups of amino acids there are two hydrophobic amino acids wherein each amino acid is a D-amino acid or glycine, and two hydrophilic D-amino acids as hereinabove noted. Thus, in a preferred embodiment, the biologically active polypeptide comprises a chain including at least four groups of amino acids, each containing four amino acids wherein each amino acid is a D-amino acid or glycine. Two of the four amino acids in each group are hydrophobic, wherein each hydrophobic amino acid is a D-amino acid or glycine, at least one amino acid is a basic hydrophilic D-amino acid, and the remaining one is a basic or neutral hydrophilic D-amino acid, with the polypeptide chain preferably having at least 20 amino acids but no greater than 50 amino acids. In one embodiment, each of the at least four groups of amino acids which are in the peptide chain is of the sequence A-B-C-D, B-C-D-A, C-D-A-B or D-A-B-C wherein A and B are hydrophobic, one of C or D is basic hydrophilic, and the other of C or D is basic or neutral hydrophilic. The resulting polypeptide chain, therefore, may have one of the following sequences: (X 1 ) a (A-B-C-D) n (Y 1) (X 2 )(B-C-D-A) n (Y 2 ) b (X 3 ) a (C-D-A-B) n (Y 3 ) b (X 4 ) a (D-A-B-C) n (Y 4 ) b wherein X 1 is D; C-D- or B-C-D-, Y 1 is -A or -A-B or -A-B-C X 2 is A-, D-A- or C-D-A- Y 2 is -B, -B-C or B-C-D X 3 is B-, A-B-, D-A-B- Y 3 is -C, -C-D, -C-D-A X 4 is C-, B-C-, A-B-C- Y 4 is -D, -D-A, -D-A-B a is o or 1; b is o or 1 and n is at least 4. It is to be understood that the peptide chain may include D-amino acids or glycine between the hereinabove noted groups of four amino acids provided that the spacing between such groups and the charge on the D-amino acids or glycine does not change the characteristics of the peptide chain which provide amphiphilicity and a positive charge and do not adversely affect the folding characteristics of the chain to that which is significantly different from one in which the hereinabove noted groups of four amino acids are not spaced from each other. As representative examples, there may be mentioned. I D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser-D-Lys II D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D D-Ser-D-Lys. III D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser- D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala- D-Phe-D-Ser-D-Lys-D-Ala- IV D-Ser-D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala- D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala- D-Phe-D-Ser-D-Lys-D-Ala-D-Phe- V D-Lys-D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser-D-Lys- D-Ala-D-Phe-D-Ser-D-Lys-D-Ala-D-Phe-D-Ser The peptide may have amino acids extending from either end of the chain. For example, the chains may have a D-Ser-D-Lys sequence before the "D-Ala" end, and/or a D-Ala-D-Phe sequence after the "D-Lys" end. Other amino acid sequences may also be attached to the "D-Ala" and/or the "D-Lys" end. Similarly, in any polypeptide chain of the present invention having at least four groups of amino acids of the sequence as described above, the chain may have, for example, a C-D sequence before the first A-B-C-D group. Also other acid sequences including D-amino acids or glycine may be attached to the "A" and/or the "D" end of one of these polypeptide chains. Also there may be D-amino acids or glycine residues in the chain which space one or more groups of the hereinabove noted four amino acids from each other. Such polypeptides are generally water-soluble to a concentration of at least 20 g/ml at neutral pH in water. Such polypeptides are non-hemolytic, i.e., it will not rupture red blood cells at effective antimicrobial concentrations. The structure of such polypeptides provides for flexibility of the polypeptide molecule. When the polypeptide is placed in water, it does not assume an amphiphilic structure. When the polypeptide encounters an oily surface or membrane, the polypeptide chain folds upon itself into a rod like structure. In accordance with a further aspect of the present invention, there is provided a peptide (polypeptide) having from eight to fifteen amino acids comprised of at least four hydrophobic amino acids and four hydrophilic amino acids. Each amino acid residue is a D-amino acid residue or glycine. The hydrophobic amino acids are in groups of two adjacent hydrophobic D-amino acids or glycine wherein each group of two hydrophobic D-amino acids or glycine is spaced from each other by at least one D-amino acid other than a hydrophobic D-amino acid or glycine (preferably at least two D-amino acids) and generally no greater than four D-amino acids, and the D-amino acid(s) between pairs of hydrophobic amino acids wherein each amino acid is a D-amino acid or glycine, may or may not be hydrophilic. The hydrophilic D-amino acids are generally also in groups of two adjacent D-amino acids in which at least one of the two D-amino acids is a basic hydrophilic D-amino acid and the other of the two is basic or neutral. The groups of two D-hydrophilic amino acids are spaced from each other by at least one amino acid other than a hydrophilic D-amino acid, and wherein the at least one amino acid is a D-amino acid or glycine (preferably at least two amino acids) and generally no greater than 4 amino acids, and the amino acids between pairs of hydrophilic amino acids may or may not be hydrophobic. The peptide having from 8 to 15 amino acids is amphiphilic and is positively charged (basic). The 8 to 15 amino acid peptide hereinabove described may or may not be bioactive, and in the case where such peptide is not bioactive, it has utility as an intermediate in providing the hereinabove noted peptides which have at least 16 amino acids and which are bioactive. For example, two peptides, one having eight D-amino acids and the other having twelve D-amino acids may be coupled to each other to form a peptide having 20 D-amino acids of the type hereinabove described and which is bioactive. The peptides may be coupled by standard peptide chemistry techniques. Thus, for example, such peptides may be condensed in solution by the technique disclosed by Johnson, et al. Peptides, pages 239-42 (Walter de Gruzter & Co., 1986). As representative examples of such peptides, there may be mentioned peptides represented by the following structure wherein A, B, C and D are as defined previously; (i) (W 1 ) a (A-B-C-D) n (Z 1 ) b (ii) (W 2 ) a (B-C-D-A) n (Z 2 ) b (iii) (W 3 ) a (C-D-A-B) n (Z 3 ) b (IV) (W 4 ) a (D-A-B-C) n (Z 4 ) b wherein W. is D-, C-D-, B-C-D- W„ is A-, D-A-, C-D-A- W 3 is B-, A-B-, D-A-B- W 4 is C-, B-C-, A-B-C- Z. is -A, -A-B, -A-B-C Z 2 is -B, -B-C, -B-C-D Z 3 is -C, -C-D, -C-D-A Z 4 is -D, -D-A, -D-A-B n is 2 or 3, a is o or 1 and b is o or 1. In accordance with yet another aspect of the present invention, there is provided a peptide which includes the following basic peptide structure X: ~ R l "R l "R 2~ R 2~ R l "R l~ R 3~ R l~ "R l "R l "R 3 "R l "R l "R 4 "R 5 -R l " wherein R. is a hydrophobic amino acid; R, is a hydrophobic amino acid or a basic hydrophilic amino acid; R, is a basic hydrophilic amino acid; R 4 is a hydrophobic or neutral hydrophilic amino acid; R 5 is a basic or neutral hydrophilic amino acid, and each amino acid residue of said peptide is a D-amino acid residue or glycine. The hereinabove basic structure is hereinafter symbolically indicated as X. Peptides formed in accordance with this basic structure are commonly referred to as CPF peptides. The CPF peptides of the present invention may include only the hereinabove noted D-amino acids or glycine or may include additional D-amino acids or glycine residues at the amino and/or carboxyl end or both the amino and carboxyl end. In general, the peptide does not include more than 40 amino acids, wherein each amino acid is a D-amino acid or glycine. The CPF peptides including the above basic structure preferably have from 1 to 4 additional amino acids at the amino end, wherein each amino acid is a D-amino acid or glycine. Accordingly, such preferred peptides may be represented by the structural formula: Y - X - wherein X is the hereinabove described basic peptide structure and Y is (i) R 5 -, or ( ii ) R 2 -R 5 "; ° r (iii) R 1 -R 2 -R 5 ; or (iv) R 2 -R-,-R 2 -R 5 preferably Glycine - R 1 -R,-R 5 . wherein R.. , R ? and R- are as previously defined. The carboxyl end of the basic peptide structure may also have additional amino acids which may range from 1 to 13 additional amino acids. In a preferred embodiment, the basic structure may have from 1 to 7 additional amino acids at the carboxyl end, which may be represented as follows: -X - Z wherein X is the hereinabove defined basic peptide structure and Z is (i) R χ -, or (ϋ) R j -R-^; or (iii) R 1 -R 1 -R 4 ; or (iv) R 1 -R 1 -R 4 -R 4 ; or (v) R 1 -R 1 -R 4 -R 4 -R f .; or (vi) R 1 -R-,-R 4 -R 4 -R g -D-Gln; or (vii) R- j -R- j -R^R^Rg-D-Gln-D-Gln, wherein R-, and R 4 are as previously defined, and R g is D-proline or a hydrophobic amino acid. Preferred peptides may be represented by the following structural formula (Y) a - X - (Z) b wherein X, Y and Z are as previously defined and a is 0 or 1 and b is 0 or 1. As representative examples of CPF peptides used in the present invention, there may be mentioned peptides represented by the following (single letter amino acid code): G12S3LG4ALKA5LKIG678LGG9(10)QQ Where: 1 = F, L 2 = G, A 3 = F, L 4 = K, L 5 = A, G, T 6 = A, T 7 = H, N 8 = A, M, F, L 9 = A, S, T 10 = P, L Preferred CPF peptides are of the following sequences: (1) GFGSFLGLALKAALKIGANALGGAPQQ (2) GLASFLGKALKAGLKIGAHLLGGAPQQ (3) GLASLLGKALKAGLKIGTHFLGGAPQQ (4) GLASLLGKALKATLKIGTHFLGGAPQQ (5) GFASFLGKALKAALKIGANMLGGTPQQ (6) GFGSFLGKALKAALKIGANALGGAPQQ (7) GFGSFLGKALKAALKIGANALGGSPQQ (8) GFASFLGKALKAALKIGANLLGGTPQQ In accordance with an aspect of the present invention, there is provided a composition comprising at least one biologically active peptide which includes at least a chain of the following 20 amino acid residues having the following peptide structure X 10 where X- 0 is: "R ll "R 12 "R ll "R ll "R 13 "R 13~ R ll "R ll "R 12 "R ll "R ll "R 15 "R 14~ R ll "R 12 "R 13 " -R 11 -R 1 g-R--.-R- 7 , wherein: R-,-, is a hydrophobic amino acid; R- 2 is a basic hydrophilic amino acid; R- 3 is a hydrophobic or basic hydrophilic amino acid; R- 4 is a netural hydrophilic amino acid, or a basic hydrophilic amino acid; R 15 is a neutral hydrophilic amino acid; R- β is D-proline or a hydrophobic amino acid; and R-- is a netural hydrophilic, "e W 4 " basic hydrophilic or hydrophobic amino acid. Each of the amino acid residues of the peptide is a D-amino acid residue or glycine. The at least one biologically active peptide which includes peptide residue X.,- has at least the hereinabove described twenty amino acid peptide and generally no greater than 35 amino acids, preferably no greater than 30 amino acids. Such peptides are derived from fragments of the human hormone cholecystokinin, or may be derivatives of such fragments. In one embodiment, the at least one biologically active peptide is of the formula R...-R.,-X-, wherein R-- is a hydrophobic amino acid as described above. Most preferably, the biologically active peptide of this embodiment includes a chain of at least the following amino acids: D-Leucine-D-Leucine-X-. In another embodiment, the at least one biologically active petpide includes a chain of at least the following amino acids: -X-R 12 -R 11 -R 15 -R 11 -R 11 -, wherein i-, R i 2' anc * R 15 are amino acids of the types hereinabove described. The peptide may be amide-terminated or carboxy-terminated. In accordance with still another aspect of the present invention, there is provided a biologically active amphiphilic peptide which includes the following basic structure X-. ' [R 2r R 22 "R 22- R 23- R 21 _R 22- R 22 ] n' wherein R 2 1 is a basic hydrophilic amino acid, R, 2 is a hydrophobic amino acid, R_ 3 is a neutral hydrophilic or hydrophobic amino acid, n is from 2 to 5, and each amino acid residue of the peptide is a D-amino acid residue or glycine. In accordance with one embodiment, the peptide may include the following structure: Y 1? -X 17 , wherein X. ? is as hereinabove described, and Y is: (i) R 22 ; (ii) R 22 -R 22 ; (iii) R 21 - R 22" R 22 ; ( iv > R 23 _R 2l "R 22~ R 22 ; ( v ) 22 - R 23 - 2i- R 22- R 22 ; or ( vi ) 22 - R 22 "R 23- R 21- R 22 "R 22' wherein R 2 1' R 22' and R 23 are as hereinabove described In accordance with another embodiment, the peptide may include the following structure: X 12 -Z- 2 , wherein X- 2 is as hereinabove described, and Z 1? IS: (Y12' .a-X12- ( z12' .b, wherein Y and Z are as previously defined, a is 0 or 1, and b is 0 or 1. In a preferred embodiment, n is 3, and most preferably the peptide is of the following structure as indicated by the single letter amino acid code: [KIAGKIA] 3 . In another embodiment, n is 2, and the peptide preferably is of the following structure as indicated by the single letter amino acid code: KIA(KIAGKIA) 2 KIAG. In accordance with another aspect of the present invention, there is provided a biologically active amphiphilic peptide which includes the following basic structure X 14 : R 2 R 22~ R 22~ R 23 "R 2 R 22~ R 22 "R 21~ R 22~ R 22~ R 22~ R 2 R 22~ R 22' wherein R 2 - R 2 2 anc R 23 are as nere m above described, and each amino acid residue of the peptide is a D-amino acid residue or glycine. In accordance with one embodiment, the peptide may include the following structure: Y, 4 -X 14 , wherein X 14 is as hereinabove described, and Y- 4 IS: (i) R 22 ; ( ii ) R 22 _R 22 ; ( iii ) R 21 _R 22" R 22 ; (iv) R 23 -R 21 -R 22 -R 22 ; < v) R 22~ R 23~ R 21~ R 22~ R 22 ; ( vi ) R 22 "R 22 "R 23 "R 2l "R 22 "R 22' or (vii) R 21 -R 22 -R 22 -R 23 -R 21 -R 22 -R 22 ,wherein R 21 , R 22 and R 23 are as hereinabove described. In accordance with another embodiment, the peptide may include the following structure: Υ. Λ 14 A ~Z14 Λ , wherein X η 14 /1 is as hereinabove described and Z1,4„ IS: (i) R 21' ( ii) R 21" R 22 ; ( iii ) R 21- R 22" R 22 ; ( iv ) R 21- R 22- R 22 _R 23 ; < v > R 2l "R 22 "R 22 "R 23 "R 21 ; ( vi ) R 21- R 22- R 22 _R 23- R 2r R 22 ; ° r ( vii ) R 21- R 22 "R 22 "R 23- R 21 "R 22- R 22' wherein R 2 1' R 22 and R 23 are as hereinabove described. In accordance with yet another embodiment the peptide may include the following structure: (Y 14 )a-X 14 -(Z-, 4 )b, wherein X and Y are as previously defined, a is 0 or 1, and b is 0 or 1. In a preferred embodiment, the peptide is of the following structural formula as indicated by the single letter amino acid code: KLASKAGKIAGKIAKVALKAL. In another preferred embodiment, the peptide is of the following structural formula as indicated by the single letter amino acid code: KIAGKIAKIAGOIAKIAGKIA. In accordance with a further embodiment, the peptide may include the following basic peptide structure X lg * "R 3l "R 33 "R 32 "R 3l "R 34 "R 34 "R 3l " "R 3l "R 34 "R 32 "R 3l "R 3l "R 32 "R 3l " _n -T? —v - κ 31 31 κ 32 wherein R_- is a hydrophobic amino acid, R__ is a basic hydrophilic amino acid, R 33 is a neutral hydrophilic, basic hydrophilic, or hydrophobic amino acid, and R 34 is a hydrophobic or basic hydrophilic amino acid, and each amino acid residue is a D-amino acid residue or glycine. Preferably, R 33 is a neutral hydrophilic amino acid. Such peptides are commonly referred to as PGLa peptides. The PGLa peptides generally include at least seventeen amino acids and may include as many as forty amino acids. Accordingly, the hereinabove described basic peptide structure for a PGLa peptide may include additional amino acids at the amino end or at the carboxyl end or at both the amino and carboxyl end. Thus, for example, a PGLa peptide may have the following structure: "Y 16 "X 16 where X-.- is a previously defined; and Y-- is: (i) R 31 ; or (ii) R 34 _R 31 where R 31 and R 34 are as previously defined. For example, a PGLa peptide may also have the following structure: "X 16 "Z 16 where X lβ is a previously defined; and Z lg is: Y 16 is (i) R 31 ; or (ii) R 3 r R 31 where R 3 - is as previously defined. A PGLa peptide may also have the following structure: ( 1 Y n 16,)'a ~ X 16~ (Z 16 ) b where X lg γ ιc anc * z ιg are as Previously defined, a is 0 or 1 and b is 0 or 1. In accordance with another embodiment, the peptide may include the following basic peptide structure X la ' —R 31 -R 33 -R 32 -R 31 -R 34 -R 35 -R 33 - R 3l "R 34 "R 32 "R 3l "R 3l 'R 32 " R 3r R 3l "R 3r R 32- (R 36 ) n- R 31-' wherein R 3 1' R 32' R 33' and R_ 4 are as previously defined, and R 35 is glutamine or asparagine or a basic hydrophilic, or hydrophobic amino acid, R 3g is glutamic acid, aspartic acid, a hydrophobic amino acid or a basic hydrophilic amino acid, and n is 0 or 1. Each amino acid residue is a D-amino acid residue or glycine. Such peptides are commonly referred to as XPF peptides. The XPF peptides generally include at least nineteen amino acids and may include up to forty amino acids. Accordingly, the hereinabove described basic peptide structure of XPF may include additional amino acids at the amino and carboxyl ends. Thus, for example, an XPF peptide may include the following structure: *18 Λ 18 where X_ g is as previously defined and Y 1S is (i) R 31 or (ii ) R 34 " R 31 where R_, and R 34 are as previously defined. An XPF peptide may include the following structure: "X 18~ Z 18~ where X- a is as previously defined and Z. Q is (i) R 31 or (ii) R 31- R 35 ; or (iii) R 3 --R 35 -D-Proline; or (iv) R 31 -R 35 -D-Proline-R 32 An XPF peptide may also have the following structure; {Y 18 } a "X 18 Z 18 ) b where X- tg/ Y la and Z- g are as previously defined, a is 0 or 1, and b is 0 or 1. Preferred are XPF or PGLa peptides, which are characterized by the following primary amino acid sequence (single letter amino acid code) : PGLa: GMASKAGAIAGKIAKVALKAL (NH 2 ) XPF: ASKIGQTGKIAKVGLKELIQPK A review of XPF and PGLa can be found in Hoffmann et al. , EMBO J. 2:711-714, 1983; Andreu et al. , J.Biochem. 149:531-535, 1985; Gibson et al. J. Biol Chem. 261:5341-5349, 1986; and Giovannini et al, Biochem J. 243:113-120, 1987. Applicants unexpectedly have found that the above-mentioned peptides, all of which consist entirely of D-amino acids or glycine residues, have biological activity. The above-mentioned peptides also have increased resistance to proteolytic enzymes while retaining their biological activity. In general, the peptides hereinabove described, and/or analogues or derivatives thereof are generally water soluble to a concentration of at least 20 mg/ml at neutral pH in water. In addition, such peptides are non-hemolytic; i.e., they will not rupture blood cells at effective concentrations. The peptides cause less than 5% hemolysis of human erythrocytes at a concentration of 500 μg/ml. In addition, the structure of such peptide provides for flexibility of the peptide molecule. When the peptide is placed in water, it does not assume an amphiphilic structure. When the peptide encounters an oily surface or membrane, the peptide chain folds upon itself into a rod-like structure. The peptides may be C-terminal acids "or amides. The peptides may be administered to a host; for example a human or non-human animal, in an amount effective to inhibit growth of a target cell or virus. Thus, for example, the peptides and/or analogues or derivatives thereof may be used as antimicrobial agents, anti-viral agents, antibiotics, anti-tumor _ _ agents, antiparasitic agents, spermicides, as well as exhibiting other bioactive functions. The term "antimicrobial" as used herein means that the peptides of the present invention inhibit, prevent, or destroy the growth or proliferation of microbes such as bacteria, fungi, or the like. The term "antibiotic" as used herein means that the peptides employed in the present invention produce effects adverse to the normal biological functions of the cell, tissue, or organism including death or destruction and prevention of the growth or proliferation of the biological system when contacted with the peptides. The term "spermicidal" as used herein means that the peptides employed in the present invention, inhibit, prevent, or destroy the motility of sperm. The term "antiviral" as used herein means that the peptides employed in the present invention inhibit, prevent, or destroy the growth or proliferation of viruses. The term anti-tumor as used herein means that the peptide inhibits the growth of or destroys tumors. The term "antiparasitic" as used herein means that the peptides of the present invention may be used to inhibit the growth of or destroy parasites. The peptides of the present invention have a broad range of potent antibiotic activity against a plurality of microorganisms including Gram-positive and Gram-negative bacteria, fungi, protozoa, and the like, as well as parasites. The peptides of the present invention allow a method for treating or controlling microbial infection caused by organisms which are sensitive to the peptides. Such treatment may comprise administering to a host organism or tissue susceptible to or affiliated with a microbial infection an antimicrobial amount of at least one of the peptides. Because of the antibiotic properties of the peptides, they may also be used as preservatives or sterilants of materials susceptible to microbial contamination. The peptide may be administered in combination with a non-toxic pharmaceutical carrier or vehicle such as a filler, non-toxic buffer, or physiological saline solution. Such pharmaceutical compositions may be used topically or systemically and may be in any suitable form such as a liquid, solid, semi-solid, injectable solution, tablet, ointment, lotion, paste, capsule, or the like. The peptide compositions may also be used in combination with adjuvants, protease inhibitors, or compatible drugs where such a combination is seen to be desirable or advantageous in controlling infection caused by harmful microorganisms including protozoa viruses, and the like, as well as by parasites. The peptides of the present invention may be administered to a host; in particular an animal, in an effective antibiotic and/or anti-tumor and/or anti-viral and/or anti-microbial and/or anti-parasitic and/or an antispermicidal amount. Depending on the use, a composition in accordance with the invention will contain an effective anti-microbial amount and/or an effective antispermicidal amount and/or an effective anti-viral amount and/or an effective anti-tumor amount and/or an effective antibiotic amount and/or anti-parasitic amount of one or more of the hereinabove described peptides which have such activity. The peptide of the present invention may also be employed in promoting or stimulating healing of a wound in a host. The term "wound healing" as used herein includes various aspects of the would healing process. These aspects include, but are not limited to, increased contraction of the wound, increased deposition of connective tissue, as evidenced by, for example, increased deposition of collagen in the wound, and increased tensile strength of the wound, i.e., the peptides increase wound breaking strength. The peptides of the present invention may also be employed so as to reverse the inhibition of wound healing caused by steroids such as cortisone. The peptides of the present invention may be used in the treatment of external burns and to treat and/or prevent skin and burn infections. In particular, the peptides may be used to treat skin and burn infections caused by organisms such as, but not limited to, P. aeruginosa and S. aureus. The peptides are also useful in the prevention or treatment of eye infections. Such infections may be caused by bacteria such as, but not limited to, P. aeruginosa, S. aureus, and N. gonorrhoeae, by fungi such as but not limited to C. albicans and A. fumiqatus, by parasites such as but not limited to A. castellani, or by viruses. The peptides may also be effective in killing cysts, spores, or trophozoites of infection - causing organisms. Such organisms include, but are not limited to Acanthamoeba which forms trophozoites or cysts, C. albicans, which forms spores, and A. fumiqatus, which forms spores as well. In general, the peptide is employed to provide peptide dosages of from 0.1 mg. to 500 mg. per kilogram of host weight. When administered topically, the peptide is used in a concentration of from .05% to 10%. The peptides may be produced by known techniques and obtained in substantially pure form. For example, the peptides may be synthesized on an automatic synthesizer. Journal of the American Chemical Society, Vol. 85, pgs. 2149-54 (1963). It is also possible to produce such peptides by genetic engineering techniques. The peptides of the present invention may be administered alone, or in combination with other such peptides. The peptides may also be administered in combination with biologically active peptides or proteins containing L-amino acid residues, such as ion channel-forming proteins, or the peptides of the present invention may be administered in combination with other active components, such as toxic ions or antibiotics. Biologically active peptides containing L-amino acid residues which may be administered in combination with the peptides of the present invention include magainin peptides, PGLa peptides, XPF peptides, cecropins, and sarcotoxins. Magainin peptides are described in Proc. Natl. Acad. Sci. , Vol. 84, pgs 5449-53 (Aug. 1987). A review of XPF and PGLa peptides may be found in Hoffman, et al., EMBOJ. , 2:711-714 (1983). Andreu, et al., J. Biochem, 149:531-535 (1985); Gibson, et al., Biochem J. , 243:113-120 (1987). The cecropins and analogues and derivatives thereof are described in Ann. Rev. Microbiol., Vol. 41, pgs, 103-26 (1987), and Christensen, et al., PNAS, Vol. 85, pgs. 5072-5076. (1988). Sarcotoxins and analogues and derivatives thereof are described in Molecular Entomotogy, pgs 369-78, Alan R. Liss, Inc. (1987). Ion channel-forming proteins or peptides which may be employed in combination with the peptides of the present invention include defensins, also known as human neutrophil antimicrobial peptides (HNP), major basic protein (MBP) of eosinophils, bactericidal permeability-increasing protein (BPI), and a pore-forming cytotoxin called variously perforin, cytolysin, or pore-forming protein. Defensins are described in Selsted, et al., J. Clin. Invest., Vol. 76, pgs. 1436-1439 (1985). MBP proteins are described in Wasmoen, et al., J. Biol. Chem. , Vol. 263, pgs. 12559-12563 (1988). BPI proteins are described in Ooi, et al. , J. Biol. Chem. Vol. 262, pgs. 14891-14894 (1987). Perforin is described in Henkart, et al., J. Ex . Med. , 160:75 (1984), and in Podack, et al. , J. Exp. Med. , 160:695 (1984). The above articles are hereby incorporated by reference. Toxic ions which may be employed in combination with the peptides of the present invention include anions such as fluoride, peroxide, and bicarbonate anions, and cations such as silver, zinc, mercury, arsenic, copper, platinum, antimony, gold, thallium, nickel, selenium, bismuth, and cadmium cations. A toxic ion is one which when introduced into a target cell inhibits and/or prevents and/or destroys the growth of the target cell. Such a toxic ion is one which in the absence of an ion channel forming peptide is unable to cross a natural or synthetic lipid membrane; in particular a cell membrane, in sufficient amounts to affect a cell adversely. The peptide and the toxic ion, whether administered or prepared in a single composition or in separate compositions, are employed in amounts effective to inhibit and/or prevent and/or destroy the growth of the target cell. In effect, the ion potentiates the action of the peptide, i.e., the amount of toxic ion is effective to reduce the maximum effective concentration of the peptide or protein for inhibiting growth of a target cell. Antibiotics which may be employed in combination with the peptides of the present invention include bacitracins, aminoglycosides, hydrophobic antibiotics, including macrolide antibiotics, penicillins, mσnobactams, or derivatives or analogues thereof. Other antibiotics which may be used (whether or not hydrophobic) in combination with the peptides of the present invention are antibiotics which are 50-S ribosome inhibitors such as lincomycin; clindamycin; and chloramphenicol; etc.; and antibiotics which have a large lipid like lactone ring, such as mystatin; pimaricin, etc. The peptide and antibiotic may be adminstered by direct administration to a target cell or by systemic or topical administration to a host which includes the target cell, in order to prevent, destroy or inhibit the growth of a target cell. Target cells whose growth may be prevented, inhibited, or destroyed by the administration of the peptides and antibiotic include Gram-positive and Gram-negative bacteria as well as fungal cells. The invention will now be further described with respect to the following examples; however, the scope of the present invention is not to be limited thereby. EXAMPLE The procedure for the following antibacterial assay is based upon the guidelines of the National Committee for Clinical Laboratory Standards, Document M7-T2, Volume 8, No. 8, 1988. A stock solution of a peptide of the followiong structural formula: KIAGKIAKIAGKIAKIAGKIA-amide, wherein each amino acid residue is a D-amino acid residue or glycine, was prepared at a concentration of 512 μg/ml in sterile deionized distilled water and stored at -70°C. The stock peptide solution is diluted in serial dilutions (1:2) down the wells of a microtiter plate so that the final concentrations of peptides in the wells are 0.25, 0.50, 1, 2, 4, 8, 16, 32, 64, 128, and 256 μg/ml. 1.5 X 10 5 CFUs/ml of either S. aureus ATCC 25923, E. coli ATCC 25922, or P. aeruginosa ATCC 27853 were added to the wells in full strength Mueller Hinton broth (BBL 11443) from a mid-log culture. The inoculum is standarized spectrophotometrically at 600nm and is vertified by colony counts. The plates are incubated for 16-20 hours at 37°C, and the minimal inhibitory concentration (MIC) for each peptide is determined. Minimal inhibitory concentration is defined as the lowest concentration of peptide which produces a clear well in the microtiter plate. The minimal inhibitory concentration of the peptide was 8 μg/ml against S. aureus, 32 μg/ml against P. aeruginosa, and 4 μg/ml against E. coli. For comparison, a stock solution of the above-mentioned peptide was prepared as hereinabove described wherein each amino acid residue was not a D-amino acid residue. This peptide was then tested as hereinabove described for MIC against S. aureus, P. aeruginosa, and E. coli. The MIC of the peptide was 8 μg/ml against S. aureus, 16 μg/ml against P. aeruginosa, and 4 μg/ml against E. coli. The above results indicate that when all residues of biologically active peptide are D-amino acid residues or glycine residues, the peptide retains its biological activity. The peptides of the present invention, whether administered alone or in combination with agents such as toxic ions, antibiotics, or other biologically active peptides or proteins as hereinabove described, may be employed in a wide variety of pharmaceutical compositions in combination with a non-toxic pharmaceutical carrier or vehicle such as a filler, non-toxic buffer, or physiological saline solution. Such pharmaceutical compositions may be used topically or systemically and may be in any suitable form such as a liquid, solid, semi-solid, injectable solution, tablet, ointment, lotion, paste, capsule or the like. The peptide and/or agent as hereinabove described may also be used in combination with adjuvants, protease inhibitors, or compatible drugs where such a combination is seen to be desirable or advantageous in controlling infection caused by harmful microorganisms including protozoa, viruses, and the like. The peptide may be administerd to a host, in particular an animal, in an effective antibiotic and/or anti-tumor and/or antiviral and/or antimicrobial and/or antispermicidal and/or antiparasitic amount, or in an amount effective to stimulate wound healing in a host. The peptides may be administerd either alone or in combination with a toxic ion, antibiotic, or ion channel forming peptide or protein as hereinabove described. When the peptide is administered in combination with a toxic ion, the activity of the peptide is potentiated. When the peptide is administered in combination with an agent as hereinabove described, it is possible to administer the peptide and agent in separate forms. For example, the agent may be administered systemically and the peptide may be administered topically. When the peptide is adminitered topically, it may be administered in combination with a water-soluble vehicle, said water-soluble vehicle being in the form of an ointment, cream, lotion, paste or the like. Examples of water-soluble vehicles which may be employed include, but are not limited to, glycols, such as polyethylene glycol, hydroxycellulose, and KY Jelly. The water-soluble vehicle is preferably free of an oily substance. The peptide may also be employed alone, or in combination with other peptides of the present invention, or in combination with peptides containing L-amino acid residues, or in combination with other active components (eg. , toxic ions, antibiotics) as hereinabove described in the form of an oral composition for oral hygiene. Such a composition may be incorporated into a wide variety of compositions and materials used for oral hygiene purposes, which include, but are not limited to, toothpastes, mouthwashes, tooth gels, and tooth powders. Such composition may thus be used to treat or prevent periodontal disease, to prevent or reduce plaque, and/or to prevent or treat or reduce dental caries. The peptide may be used to inhibit, prevent, or destroy the growth of Streptococcus mutans, which is associated with dental caries and periodontal disease. Numerous modifications and variations of the present invention are possible in light of the above teachings and, therefore, within the scope of the accompanying claims, the invention may be practiced other than as particularly described.

Claims: WHAT IS CLAIMED IS: 1. A compound comprising: an analogue of Magainin I peptide or Magainin II peptide, said Magainin I peptide or Magainin II peptide being in an amide-or carboxy-terminated form, and wherein Magainin I is respresented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A G K F G K A F V G E I M K S 1 2 3 45 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23, and wherein each amino acid residue is a D-amino acid residue or a glycine residue, and wherein Magainin II is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A K K F G K A F V G E I M N S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2021 22 23, and wherein each amino acid residue is a D-amino acid residue or a glycine residue, and wherein said Magainin I or Magainin II peptide is substituted in at least one of positions 1-23, wherein the substituents which may be employed in each of positions 1-23 are shown in the following table: Residue No . Substituent 1 D-Lys , D-Ala 2 D-Lys , D-Ala, D- I le , D-Arg, D-Leu, D-Val , D-His , D-Met 3 D-Lys, D-Ala, D-Trp, D-Arg, D-Hi s 4 D-Lys , D-Ala, D-Arg, D-His 5 D-Phe , D-Ala , D-Lys , D-Trp , D-Leu , D- I le , D-Val , D-Met 6 D-Leu, D-Lys , D-Ala , D- He , D-Val , D-Met 7 D-Lys , D-Hi s , D-Ala , D-Arg , D- He , D-Val , D-Met 8 D-Ala, D-Lys, D-Ser, D-Trp, D-Met, D- He , D-Arg, D-His, D-Thr , D-Leu, D-Val 9 D-Lys , D-Ala , D-Trp , D-Arg , D-Hi s , D-Leu , D- He , D-Val 10 D-Lys D-Ala , D-Trp , D-Arg, D-Hi s , D-Leu , D- He , D-Val 11 D-Lys,D-Arg,D-His 12 D-Phe,D-Lys,D-Trp,D-Arg,D-His 13 D-Ala,D-Lys,D-Trp,D-Met,D-Arg,D-His,D-Phe,D-Leu, D-He,D-Val 14 D-Ala,D-Lys,D-Arg,D-His 15 D-Lys , D-Trp , D-D-Ala , D-Arg, D-Hi s , D-Phe 16 D-Ala, D-Lys , D-Phe , D- He , D-Val , D-Met , D-Leu 17 D-Ala , D-Lys , D-Val , D-Trp , D-Arg, D-Hi s , D-Met , D-Leu 18 D-Ala,D-Lys,D-Trp,D-Arg,D-His,D-Leu,D-Met 19 D-Ala, D-Lys , D-Glu , Gly , D-Arg, D-Hi s , D-Leu D- He , D-Phe , D-Asn 20 D- He , D-Ala, D-Lys , D-Trp, D-Leu , D-Phe , D-Val , D-Met 21 D-Lys , D-Pro , D-Al , D-Hi s , D-Leu , D-Arg , D- He , D-Phe 22 D-Lys, D-Ala, D-Asn, D-Gln, D-Arg, D-His 23 D-Ser, D-Lys, D-Ala, D-Thr, Gly, D-Leu, D- He , D-Gln, D-Asn 2. The compound of Claim 1 wherein said Magainin I or Magainin II peptide is substituted in at least one of positions 1-23, wherein each of the substituents in each of positions 1-23 is shown in the following table: an analogue of Magainin I peptide or Magainin II peptide, said Magainin I peptide or Magainin II peptide being in an amide-or carboxy-terminated form, and wherein Magainin I is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A G K F G K A F V G E I M K S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23, and wherein each amino acid residue is a D-amino acid residue or a glycine residue, and wherein Magainin II is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A K K F G K A F V G E I M N S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23, and wherein each amino acid residue is a D-amino acid residue or a glycine residue, and wherein at least one of amino acid residues 15-23 is omitted, and wherein said Magainin I or Magainin II peptide is substituted in at least one of the remaining positions 1-23, wherein the substituents which may be employed in each of positions 1-23 are shown in the following table: Residue No . Substituent 1 D-Lys , D-Ala 2 D-Lys, D-Ala, D- I le, D-Arg, D-Leu, D-Val , D-His , D-Met 3 D-Lys , D-Ala, D-Trp , D-Arg, D-His 4 D-Lys , D-Ala, D-Arg, D-His 5 D-Phe , D-Ala , D-Lys , D-Trp , D-Leu , D- He , D-Val , D-Met 6 D-Leu , D-Lys , D-Ala , D- He , D-Val , D-Met 7 D-Lys , D-Hi s , D-Ala , D- Arg, D- He , D-Val , D-Met 8 D-Ala , D-Lys , D-Ser , D-Trp , D-Met , D- He , D-Arg , D-Hi s , D-Thr, D-Leu, D-Val 9 D-Lys , D- Al a , D-Trp , D-Arg , D-Hi s , D-Leu , D- He , D-Val 10 D-Lys , D-Ala , D-Trp , D-Arg, D-Hi s , D-Leu , D- He , D-Val 11 D-Lys, D-Arg, D-His 12 D-Phe, D-Lys, D-Trp, D-Arg, D-His 13 D-Ala, D-Lys , D-Trp , D-Met , D-Arg, D-His , D-Phe , D-Leu , D- He , D-Val 14 D-Ala, D-Lys, D-Arg, D-His 15 D-Lys , D-Trp , D-Ala , D-Arg, D-Hi s , D-Phe 16 D-Ala , D-Lys , D-Phe , D- He , D-Val , D-Met , D-Leu 17 D-Ala, D-Lys , D-Val , D-Trp, D-Arg, D-His, D-Met, D-Leu 18 D-Ala , D-Lys , D-Trp , D-Arg , D-Hi s , D-Leu, D-Met, D-Phe 19 D-Ala , D-Lys , D-Glu , Gly , D-Arg, D-Hi s , D-Leu , D- He , D-Phe , D-Asn 20 D- He , D-Ala , D-Lys , D-Trp , D-Leu , D-Phe , D-Val , D-Met 21 D-Lys , Pro , D-Ala , D-Hi s , D- Leu , D-Arg , D- He , D-Phe 22 D-Lys, D-Ala, D-Asn, Gin, D-Arg, D-His 23 D-Ser, D-Lys , D-Ala, D-Thr, Gly, D-Leu, D- I le , D-Gln, D-Asn 4. The compound of Claim 3 wherein said Magainin I or Magainin II peptide is substituted in at least one of the remaining positions 1-23, wherein each of the substituents in each of positions 1-23 is shown in the following table: Residue No. Substituent 1 D-Lys,D-Ala 2 D-Lys,D-Ala,D-Ile 3 D-Lys,D-Ala,D-Trp 4 D-Lys,D-Ala 5 D-Phe,D-Ala,D-Lys,D-Trp 6 D-Leu,D-Lys,D-Ala 7 D-Lys,D-His,D-Ala 8 D-Ala,D-Lys,D-Ser,D-Trp 9 D-Lys,D-Ala,D-Trp 10 D-Lys,D-Ala,D-Trp 11 D-Lys 12 D-Phe,D-Lys,D-Trp 13 D-Ala,D-Lys,D-Trp 14 D-Ala,D-Lys 15 D-Lys,D-Trp,D-Ala 16 D-Ala,D-Lys,D-Phe 17 D-Ala,D-Lys,D-Val,D-Trp 18 D-Ala,D-Lys,D-Trp 19 D-Ala,D-Lys,D-Glu 20 D-Ile,D-Ala,D-Lys,D-Trp 21 D-Lys,D-Pro,D-Ala 22 D-Lys,D-Ala,D-Asn 23 D-Ser,D-Lys,D-Ala 5. A compound, comprising: a deletion analogue of an amide or carboxy terminated Magainin I wherein Magainin I is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: _ _ G I G K F L H S A G K F G K A F V G E I M K S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23, and wherein each amino acid residue is a D-amino acid residue or a glycine residue, and at least one of amino acids 15 through 23 is omitted. 6. The compound of Claim 5 wherein at least one of amino acids 15, 16, 18, 19, 21, 22 and 23 is omitted. 7. A compound comprising: a deletion analogue of an amide or carboxy terminated Magainin II wherein Magainin II is represented by the following structural formula using the single letter amino acid code and the numbers below each amino acid residue refer to the position of the residue in the peptide: G I G K F L H S A K K F G K A F V G E I M N S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2021 22 23, and wherein each amino acid residue is a D-amino acid residue or a glycine residue, and at least one of amino acids 15 through 22 is omitted. 8. The compound of Claim 7 wherein at least one of amino acids 15, 18, 19, 20, 21, and 22 is omitted. 9. A peptide comprising: said peptide containing at least eight amino acids, wherein each amino acid is a D-amino acid or glycine, said peptide containing at least two groups of amino acids A-B wherein each A-B group is separated from another A-B group by at least one D-amino acid other than a hydrophobic amino acid and at least two groups of D-amino acids C-D wherein each C-D group is separated from another C-D group by at least one D-amino acid or glycine other than a hydrophilic D-amino acid, wherein each of A and B is a hydrophobic D-amino acid or glycine wherein each of A and B may be the same or different amino acids and one of C and D is a basic hydrophilic D-amino acid and the other of C and D is a basic or neutral hydrophilic D-amino acid. 10. The peptide of Claim 9 wherein the peptide has from 8 to 15 amino acids. 11. The peptide of Claim 10 wherein the peptide includes one of the following sequences: (i) (W 1 ) a (A-B-C-D) n (Z 1 ) b (ii) (W 2 ) a (B-C-D-A) n (Z 2 ) b (iii) (W 3 ) a (C-D-A-B) n (Z 3 ) b (IV) (W 4 ) a (D-A-B-C) n (Z 4 ) b wherein W-, is D-, C-D-, B-C-D- W 2 is A-, D-A-, C-D-A- W 3 is B-, A-B-, D-A-B- W 4 is C-, B-C-, A-B-C- Z. is -A, -A-B, -A-B-C Z, is -B, -B-C, -B-C-D Z 3 is -C, -C-D, -C-D-A Z 4 is -D, -D-A, -D-A-B n is 2 or 3 , a i s o or l and b is o or 1 . 12. The peptide of Claim 9 wherein the peptide contains at least 16 amino acids and there are at least four groups of amino acids A-B and at least 3 groups of D-amino acids C-D. 13. The peptide of Claim 12 wherein there are at least four groups of D-amino acids C-D. 14. The peptide of Claim 13 wherein the peptide includes at least four groups of the peptide sequence -A-B-C-D, -B-C-D-A-, -C-D-A-B, -D-A-B-C. 15. The peptide of Claim 14 wherein the peptide includes one of the following sequences: (X 1 ) a (A-B-C-D) n (Y 1) (X 2 ) a (B-C-D-A) n (Y 2 ) b ( χ 3 ) a( C-D-A-B) n (Y 3 ) b (X 4 ) a (D-A-B-C) n (Y 4 ) b wherein X- is D; C-D- or B-C-D-, Y-, is -A or -A-B or -A-B-C X_ is A-, D-A- or C-D-A- Y, is -B, -B-C or B-C-D X 3 is B-, A-B-, D-A-B- Y 3 is -C, -C-D, -C-D-A X 4 is C-, B-C-, A-B-C- Y 4 is -D, -D-A, -D-A-B a is o or 1; b is o or 1; and n is at least 4. 16. The peptide of Claim 13 wherein said hydrophobic amino acids are selected from the class consisting of D-Ala, D-Phe, Gly, D-Ile, D-Leu, D-Met, D-Val, D-Trp, and D-Tyr and D-Cys, said neutral hydrophilic D-amino acids are selected from the class consisting of D-Asn, D-Ser, D-Gln, and D-Thr, and said basic hydrophilic D-amino acids are selected from the class consisting of D-Lys, D-Arg, D-His, and D-ornithine. 17. The polypeptide of Claim 16 wherein at least one of said at least four groups of said four amino acids is of the sequence A-B-C-D, wherein A and B are hydrophobic amino acids, one of C and D is a neutral or basic hydrophilic amino acid, the other of C or D is a basic hydrophilic amino acid. 18. The polypeptide of Claim 13 wherein said polypeptide includes the following sequence: -(D-Ala-D-Phe-D-Ser-D-Lys) 4 - 19. The polypeptide of Claim 14 wherein said polypeptide comprises a chain of at least 20 amino acids and no greater than 50 amino acids. 20. The polypeptide of Claim 14 wherein said polypeptide includes five groups of said sequence. 21. The polypeptide of Claim 14 wherein said polypeptide includes six groups of said sequence. 22. "* The polypeptide of Claim 9 wherein said polypeptide includes repeating groups of said four amino acids. 23. A compound, comprising: a peptide, said peptide including the following basic structure X: "R l "R l "R 2 "R 2 "R l "R l "R 3 "R l " -R 1 -R 1 -R 3 -R 1 -R 1 -R 4 -R 5 -R 1 wherein R.. is a hydrophobic amino acid; R ? is a basic hydrophilic amino acid or a hydrophobic amino acid, R_ is a basic hydrophilic amino acid, R 4 is a hydrophobic or neutral hydrophilic amino acid, and R 5 is a basic or neutral hydrophilic amino acid, and each amino acid residue of said peptide is a D-amino acid or glycine. 24. The composition of Claim 23 wherein the peptide includes the following structure: Y - X - wherein X is the basic peptide structure of Claim 2 and Y is R 5 _ ; R 2 -R 5 ~; R,-R 2 ~R 5 - or R 2 -R.,-R 2 -R ς . 25. The composition of Claim 23 wherein the peptide includes the following basic structure - X - Z- wherein X is the basic peptide structure of Claim 2 and Z is: R-^; R-^-R-^; R-^-R^-R 4 ; R^-R^-R 4 "R 4 ; R^-R-^-R^R^Rg; R-,-R-,-R 4 -R 4 -Rg-D-Gln; or R.-R- j -R.-R 4 -R--D-Gln-D-Gln, wherein R, is D-proline or a hydrophobic amino acid. 26. The composition of Claim 23 wherein the peptide includes the following basic structure. (Y) a - X - (Z) b wherein Y and Z are as previously defined in Claims 24 and 25, a is 0 or 1, and b is 0 or 1. 27. The composition of Claim 23 wherein the peptide has the following structure: G12S3LG4ALKA5LKIG678LGG9(10)QQ Where: 1 = F, L 2 = G, A 3 = F, L 4 = K, L 5 = A, G, T 6 = A, T 7 = H, N 8 = A, M, F, L 9 = A, S, T 10 = P, L 28. A composition comprising at least one biologically active peptide, said at least one biologically active peptide including a chain of at least 20 amino acids of the structure X 10 , wherein each of said at least 20 amino acids is a D-amino acid or glycine, and wherein X.,- is of the formula: "R ll "R 12 "R ll "R ll "R 13 "R 13 "R ll "R ll "R 12 "R ll "R ll "R 15 "R 14 "R ll "R 12 "R 13 " R- j ,-R 1g -R-, 5 -R 1 _ 7 -, wherein: R-. is a hydrophobic amino acid; R 12 is a basic hydrophilic amino acid; R 1 _ is a hydrophobic or basic hydrophilic amino acid; R 14 is a netural hydrophilic amino acid, or a basic hydrophilic amino acid; R-,-. is a neutral hydrophilic amino acid, R 1β is D-proline or a hydrophobic amino acid; and R-_ is a neutral hydrophilic, basic hydrophilic or hydrophobic amino acid, said at least one biologically active peptide having no greater than 35 amino acids. 29. The composition of Claim 28 wherein said at least one biologically active peptide has no greater than 30 amino acids. 30. The composition of Claim 28 wherein said at least one biologically active peptide is " of the structure: -R 11 -R 11 -X-. 31. The composition of Claim 30 wherein said at least one biologically active peptide is of the structure: D-Leucine-D-Leucine-X-. 32. The composition of Claim 28 wherein said at least one biologically active peptide is of the structure: -X-R 12 -R 11 -R 15 -R 11 -R 11 -. 33. A biologically active amphiphilic peptide, said peptide including the following basic structure X 12 * - [R 2 R 22- R 22- R 23- R 2r R 22- R 22 ]_ n' wherein R 21 is a basic hydrophilic amino acid, R ? _ is a hydrophobic amino acid, R 23 is a neutral hydrophilic or hydrophobic amino acid, and n is from 2 to 5, and wherein each amino acid residue of said peptide is a D-amino acid residue or a glycine residue. 34. The peptide of Claim 1 wherein the peptide includes the following structure: Y- 2 -X 12 , wherein X. 2 is the basic peptide structure of Claim 1, and Y 12 is: (i) R 22 ; (ii) R 22 - 22 ; ( iii ) R 2i" R 22" R 22 ; (iv) R 23 -R 21 -R 22 -R 22 ; < v > R 22 "R 23 _R 2l "R 22~ R 22 θr ( vi ) R 22~ R 22 "R 23 "R 21~ R 22~ R 22 • 35. The peptide of Claim 33 wherein the peptide includes the following basic structure: X 12 -Z 12 -, wherein X 12 is the basic peptide structure of Claim 1 and Z 12 is: (i) "21' (ii) l 2 2 1 1 -- ;R 22 ; ( iii ) R 2i~ R 22" R 22 (iv) R 2i" R 2 2' R 22" R 23 ; (v) R 21 - R 22 - R 22- R 23- R 21 ;θr (vi) R 2i- R 22 "R 22 "R 23 "R 21 "R 22- 36. The peptide of Claim 33 wherein the peptide includes the following basic structure: (Y, 2 ) -X-, 2 -(Z 12 ) b , wherein Y 12 and Z 12 are as previously defined in Claims 34 and 35, a is 0 or 1, and b is 0 or 1. 37. The peptide of Claim 33 wherein n is 3. 38. The peptide of Claim 37 wherein said peptide is of the following structural formula as indicated by the single letter amino acid code. [KIAGKIA] 3 . 39. The peptide of Claim 33 wherein n is 2. 40. The peptide of Claim 39 wherein said peptide is of the following structural formula as indicated by the single letter amino acid code: KIA(KIAGKIA) 2 KIAG. 41. A biologically active amphiphilic peptide, said peptide including the following basic structure: X-i * : R 21~ R 22~ R 22~ R 23~ R 21~ R 22~ R 22~ R 21~ R 22~ R 22~ R 22~ R 21~ R 22~ R 22' wherein R ?1 is a basic hydrophilic amino acid, R_ 7 is a hydrophobic amino acid, and R 23 is a neutral hydrophilic or a hydrophobic amino acid, and wherein each amino acid residue of said peptide is a D-amino acid residue or a glycine residue. 42. The peptide of Claim 41 wherein the peptide includes the following structure: Y .-X-., wherein X« 4 is the basic peptide structure of Claim 41, and Y... is: (i) R 22 ; (ii) R 22 - R 22 ; (iii) R 2i" R 22" R 22 ; (iv) R 23 -R 21 -R 22 -R 22 ; * v > R 22~ R 23~ R 21~ R 22~ R 22 ; (vi) R 22 - R 22 - R 23 - R 21 "R 22 "R 22' or (vii) R 21 -R 22 -R 22 -R 23 -R 21 -R 22 -R 22 . 43. The peptide of Claim 41 wherein the peptide includes the following structure: X 14 ~ Z 14 ' wnere i n X I A i s tne basic peptide structure of Claim 41 and Z 14 is: (i) R 21 ; (ii) 21 - R 22 ; (iii) R 21 -R 22 -R 22 ; ( iv ) R 2i "R 22" R 22~ R 23 ; (V) R 21 -R 22 -R 22 -R 23 -R 21 ; (vi ) R 21 -R 22 -R 22 -R 23 -R 21 -R 22 ; or (vii ) R 2i _R 22 "R 22 "R 23~ R 2l "R 22 "R 22 ' 44. The peptide of Claim 41 wherein the peptide includes the following basic structure: (Y-. 4 )a-(X 14 )-(Z 14 )b, wherein Y- 4 and Z 14 are as previuosly described in Claims 42 and 43, a is 0 or 1 and b is 0 or 1. 45. The peptide of Claim 44 wherein said peptide is of the following structural formula as indicated by the single letter amino acid code: KLASKAGKIAGKIAKVALKA . 46. The peptide of Claim 44 wherein said peptide is of the following structural formula as indicated by the single letter amino acid code: KIAGKIAKIAGOIAKIAGKIA. 47. A biologically active amphiphilic peptide, said peptide including the following basic structure X 16 " ~~ R 31~ R 33~ R 32~ R 31~ R 34~ R 34~ R 31~ R 31~ R 34~ R 32 ""R 3l "R 3l "R 32~ R 3l "R 3l "R 31~ R 32~' wherein R 31 is a hydrophobic amino acid, R 32 is a basic hydrophilic amino acid, R 33 is a neutral hydrophilic, basic hydrophilic, or hydrophobic amino acid, and R 34 is a hydrophobic or basic hydrophilic amino acid, and wherein each amino acid residue of said peptide is a D-amino acid residue or a glycine residue. 48. The peptide of Claim 47 wherein the peptide includes the following structure γ ι g~ x ιg wherein X-. β is the basic peptide structure of Claim 47, and Y.,g is: (i) R 31 ; or (ii) R 34 - R 31 . 49. The peptide of Claim 47 wherein the peptide includes the following structure: X,g "Z- je / wherein X.g is the basic peptide structure of Claim 47 and Z.g is: (i) R 31 ; or (ii) R 31 - R 31 . 50. The peptide of Claim 47 wherein the peptide includes the following basic structure: (Y 1β )a - (X-i c ) -(Z. g )b, wherein Y lβ and Z lfi are as previously described in Claims 48 and 49, a is 0 or 1, and b is 0 or 1. 51. A biologically active amphiphilic peptide, said peptide including the following basic structure X- jp " —R 31 -R 33 -R 32 -R 31 -R 34 -R 35 -R 33 -R 31 -R 34 - R 32~ R 31~ R 31~ R 32~ R 3l "R 31~ R 31~ R 32~ (R 36 ) n~ R 31~' wherein R 31 is a hydrophobic amino acid, R__ is a basic hydrophilic amino acid, R 33 is a neutral hydrophilic, basic hydrophilic, or hydrophobic amino acid, R 34 is a hydrophobic or basic hydrophilic amino acid, R-- is glutamine or asparagine, or a basic hydrophilic, or hydrophobic amino acid, and R 36 is glutamic acid, aspartic acid, a hydrophobic amino acid, or a basic hydrophilic amino acid, and n is 0 or 1, and wherein each amino acid residue is a D-amino acid residue or glycine. 52. The peptide of Claim 51 wherein said peptide includes the following structure: Y-„ - X-i r wherein X- g is the basic peptide structure of Claim 51, and Y-. fi is: (i) R 31 ; or (ii) 34 - R 31 - 53. The peptide of Claim 51 wherein said peptide includes the following structure: X- Q - . Q , where X.„ is the basic peptide structure of Claim 51, and Z. Q is: (i) R 31 ; (ii) R 31 - R 35 ; or (iii) R 31 -R 3 ---D-Proline; or (iv) R 3 --R 35 -D-Proline-R 32 . 54. The peptide of Claim 51 wherein the peptide includes the following basic structure: (Y 18 )a " (X 18> " (Z 18> b ' wherein Y.g and Z lg are as previously described in Claims 52 and 53, a is 0 or 1, and b is 0 or 1. 55. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the compound of Claim 1. 56. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the compound of Claim 3. 57. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the compound of Claim 5. 58. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the compound of Claim 7. 59. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the pepetide of Claim 9. 60. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the peptide of Claim 23. 61. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the composition of Claim 28. 62. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the peptide of Claim 33. 63. A process for inhibiting growth of target cell or virus, comprising: administering to a host an effective amount of the peptide of Claim 41. 64. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the peptide of Claim 47. 65. A process for inhibiting growth of a target cell or virus, comprising: administering to a host an effective amount of the peptide of Claim 51.

Inventors: MALOY W LEE, MALOY, W., LEE
Applicants: MAGAININ SCIENCES INC, MAGAININ SCIENCES INC.
Application year: 1991
Main classification: A61K37
IPC codes: A61K38, A61P31, C07K7, C07K14