A NEW 78 RESIDUE POLYPEPTIDE (NK-LYSINE) AND ITS USE

Abstract: A 78 residue polypeptide comprising the following amino acid sequence: GYFCESCRKIIQKLEDMVGPQPNEDTVTQAASQVCDKLKILRGLCKKIMRSFLRRISWDILTGKKPQAICVDIKICKE and functional derivatives and pharmaceutically acceptable salts thereof, said sequence comprising intra-linked half-cysteines; pharmaceutical composition containing such polypeptide as an active ingredient; a method for inhibiting microbial growth and cancer cell growth in animals including man; and nucleotide sequence corresponding to such polypeptide.

Description: A new 78 residue polypeptide (NK-lysine) and its use The present invention relates to a new polypeptide, its therapeutic use, pharmaceutical compositions contai- ning same as an active ingredient and a method for inhibi¬ ting microbial growth. The upper part of the small intestine is under normal healthy conditions almost sterile and could therefore be expected to produce antimicrobial .peptides. In 1987 a pro- gram was started for the identification of such peptides using the large scale fractionation scheme devised for the isolation of peptide hormones produced in the porcine small intestine [Mutt, V. 1986. Question answered and rai¬ sed by work on the chemistry of gastrointestinal and cere- brogastrointestinal hormonal polypeptides. Chem Scr. 26B: 191-207] . This project has earlier yielded five antibacte¬ rial peptides, the present paper describes the sirth one. The two first peptides, cecropin PI [Lee, J.-Y., , Boman, S. Chuanxin, M. Andersson, H. Jόrnvall, V. Mutt ε H.G. Boman. 1989. Antibacterial peptides from pig intestine: Isolation of a mammalian cecropin. Proc. Natl. Sci. USA. 86: 9159-9162] and PR-39 [Agerberth, B., J.-Y. Lee, T. Bergman, M. Carlquist, H.G. Boman, V. Mutt and H. Jornvall, 1991. Amino Acid Sequence of PR-39 - Isolation from Pig Intestine of a New Member of the Family of Pro- line-Arginine-Rich Antibacterial Peptides. Eur J Biochem. 202: 849-854], showed both potent activity against several Gram-negative bacteria. They also act on Bacillus megate- rium but they do not act on other Gram-positive bacteria like Staphylococcus . Cecropin PI was clearly related to the insect cecropins and was related to two proline-rich peptides from bovine phagocytes. The next three peptides to be identified [Agerberth, B., A. Boman, M. Andersson, H. JSrnvall, V. Mutt and H.G. Boman. 1993. Isolation of three antibacterial peptides from pig intestine: gastric inhibitory polypeptide (7-42), diazepam-binding inhibitor (32-86) and a novel factor, peptide 3910. Eur. J. Biochem. 216: 623-629] were active against B.megaterium but not against E. coli and two of these turned out to be derived from earlier known hormones, GIP (gastric inhibitory poly¬ peptide) and DB1 (diazepam-binding inhibitor). The intestine is an organ rich in blood vessels and peptides isolated from intestine can originate from blood cells. Thus, PR-39 was recently shown to be produced in the pig bone marrow rather than in the intestine [Storici, P. and M. Zanetti 1993. A cDNA derived from pig bone mar- row cells predicts a sequence identical to the intestinal antibacterial peptide PR-39. Biochem. Biophys. Res. Comm. 196: 1058-1065] and this applies also to the protegrin PG- 2 [Storici, P. and M. Zanetti, 1993. A cDNA derived from pig bone marrow cells predicts a sequence identical to the intestinal antibacterial peptide PR-39. Biochem. Biophys. Res. Comm. 196: 1058-1065] a peptide earlier isolated from pig phagocytes. Defensin-like peptides, cryptins, have been isolated from murine small intestine and human Paneth cells express a gene for a definsin-like peptide. Defensins were-earlier found in circulating phago¬ cytes of a number of mammals [Lehrer, R.I. and Ganz, T. 1992. Defensins - Endogenous Antibiotic Peptides from Human Leukocytes. In Secondary Metabolites: Their Function and Evolution, p 276-293, Ciba Foundation Symposia No. 171. John Wiley & Sons Ltd., Chichester, P019 1UD, UK]. Bovine phagocytes contain a number of different peptide antibiotics: A small dodeca peptide with two cysteines called bactenecin [Romeo, D., B. Skerlavaj, M. Bolognesi and R. Gennaro, 1988. Structure and bactericidal activity of an antibiotic dodecapeptide purified from bovine neutrophils. J.Biol.Chem. 263: 9573-9575], two larger Proline-rich peptides, Bac5 and Bac7, [Frank, R.W., R. Gennaro, K. Schneider, M. Przybylski and D. Romeo. 1990. Amino acid sequences of two proline-rich bactenecins Antimicrobial peptides of bovine neutrophils. J.Biol.Chem. 265: 18871-18874] and a tryptophan-rich peptide, indolicidin [Selsted, M.E., M.J. Novotny, W.L. Morris, Y.Q. Tang, W. Smith and J.S. Cullor, 1992. Indolicidin, a Novel Bactericidal Tridecapeptide Amide from Neutrophils. J.Biol.Chem 267: 4292-4295]. Bovine phagocytes also contain 13 different β-defensins [Selsted, M.E., Y.-Q. Tang, W.L. Morris, P.A. McGuire, M.J. Novotny, W. Smith, A.H. Henschen and J.S. Cullor, 1993. Purification, primary structures, and antibacterial activities of 5-defensins, a new family of antimicrobial peptides from bovine neutro¬ phils. J.Biol.Chem. 268: 6641-6648], a type first found in bovine trachea [Diamond, G., M. Zasloff, H. Eck, M. Brasseur, W.L. Maloy and C.L. Bevins, 1991. Tracheal anti¬ microbial peptide, a cysteine-rich peptide from mammalian tracheal mucosa: Peptide isolation and cloning of a cDNA. Proc. Natl. Acad. Sci. USA. 88: 3952-3956]. Peptide antibiotics are common in both invertebrates and vertebrates and they are believed to be important components of the innate immunity in many animals. In some cases the effect of antibacterial peptides are not restricted to microbes. Defensins are cytolytic to a variety of mammalian cells including tumor cells [Lehrer, R.I., A.K. Lichtenstein and T. Ganz, 1993. Defen¬ sins: Antimicrobial and cytotoxic peptides of mammalian cells. Annu Rev Immunol. 11: 105-128] and bactenecin (con¬ trary to peptides like cecropin PI, magainin and apidae- cin) was recently shown to exhibit a selective toxicity for neuronal and glia cells [Radermacher, S.W., V.M. Schoop and H.J. Schluesener. 1993. Bactenecin, a leukocy- tic antimicrobial peptide, is cytotoxic to neuronal and glial cells. Journal of Neuroscience Research. 36: 657- 662]. The present invention has for its object to provide a new polypeptide which is biologically active. Another object of the invention is to provide a new polypeptide having antimicrobial activity against bacteria and also lytic activity vis-a-vis several human cancer cell lines. Yet another object of the invention is to provide pharmaceutical compositions containing such polypeptide as an active ingredient. A further object of the invention is to provide a nucleotide sequence which in an appropriate expression system is capable of expressing such polypeptide. Still another object of the invention is to provide a method for inhibiting microbial growth and growth of can¬ cer cells in animals including man. For these and other objects that will be clear from the following disclosure the invention provides for a po¬ lypeptide comprising the following amino acid sequence: GYFCESCRKIIQKLEDMVGPQPNEDTVTQAASQVCDKLKILRGLCKKIMRSFLRRISW DILTGKKPQAICVDIKICKE including also functional derivatives thereof. In said se¬ quence the half-cystines are intra-linked as shown in Fig. 3. The new polypeptide according to the invention finds therapeutic applications, such as use as an antimicrobial agent or use based on its lytic activity against NK sensi¬ tive tumor cell lines of murine or human origin (see Fig. 4). The lytic activity is particularly useful against tumor cell lines of murine or human origin. The invention also covers a pharmaceutical composi¬ tion containing as an active ingredient the polypeptide as defined above in an effective amount together with a phar¬ maceutically acceptable carrier or diluent. Said amount is suitably antimicrobially active, such as antibacterially active. The carrier or diluent is pre¬ ferably adapted for oral, intraveneous, intramuscular or subcutaneous administration. Finally, the invention includes a method for inhibi- ting microbial growth in animals, such as mammals inclu¬ ding man, said method comprising the step of administering to an animal subject to a disorder caused by microbial at- tack a polypeptide as defined above, a functional deriva¬ tive thereof or a composition as defined above in an inhi¬ bitory amount. Such method can be directed to inhibiting tumor cell growth in animals or can be directed to intestinal use constituted by oral administration of a composition as de¬ fined above in a slow release form. The method can also be directed to administration by injection of such a composi¬ tion in an injectible dose form. With regard to the expression "functional derivatives thereof" it is well known in regard to the technical area to which the present invention pertains that minor amino acid substitutions can be made to the polypeptide which do not affect or do not substantially affect the function of the polypeptide. Determination of conceivable substitu¬ tions is accomplished according to procedures well known to those skilled in the art. Thus, all polypeptides having substantially the same amino acid sequence and substan¬ tially the same biological activity, such as antimicrobial and lytic activity, are within the scope of this inven¬ tion. Also within the scope of the present invention are pharmaceutically acceptable salts of the polypeptides of this invention. Such salts are formed by methods well known to skilled artisans. Thus, for example base salts of the polypeptides can be prepared according to conventional methods. When in the instant disclosure including the claims the term polypeptide is used said term is intended to include both functional derivatives and pharmaceutical- ly acceptable salts of the polypeptide. The active polypeptide according to the present in¬ vention can be formulated for use in human or veterinary medicine for therapeutic or prophylactic use. The active preparations are normally administered orally, rectally or parenterally, such as by injection in the form of a phar¬ maceutical preparation or composition comprising the ac¬ tive constituents in combination with a pharmaceutically acceptable carrier which may be solid, semi-solid or li¬ quid, or contained in a capsule, such as when orally admi¬ nistered. The administration may also take the form of to¬ pical application. As examples of pharmaceutical prepara- tions there may be mentioned tablets, drops, solutions and suppositories. Usually, the active constituent constitutes the minor part of the preparation, such as from about 0.1 to about 50% thereof based on weight. In order to prepare pharmaceutical compositions in the form of dose units for oral application the polypep¬ tide of the invention can be mixed with a solid, pulveru¬ lent or other carrier, for example lactose, saccharose, sorbitol, mannitol, starch, such as potatoe starch, corn starch, millopectine, cellulose derivative or gelatine, and may also include lubricants, such as magnesium or cal¬ cium stearate, or polyethylene glycol waxes compressed to the formation of tablets or bodies for dragees. The dose units may also be presented in a coated form of enteric type. By using several layers of the carrier or diluent tablets operating with slow release can be prepared. Liquid preparations for oral application or for in¬ jection can be made in the form of elexirs, syrups or suspensions, for example solutions containing from 0.1 to 20% by weight of active substance, sugar and a mixture of ethanol, water, glycerol, propyleneglycol and possibly other additives of a conventional nature. The dose by which the active constituent is adminis¬ tered may vary within wide limits and is dependent on dif- ferent factors, such as the seriousness of the disorder, the age and the weight of the patient and can be adjusted individually. The invention will now be described by non-limiting examples with reference to the appended drawings, wherein Figures 1A to ID illustrate purification of NK- lysine; Figure 2 illustrates structural analysis of NK- lysine; Figure 3 shows an alignment analysis of NK-lysine and NKG5; Figure 4 illustrates the nucleotide sequence corre¬ sponding to NK-lysine; and Figure 5 illustrates a diagram showing the cytolytic activity of NK-lysine against two tumor cell lines. Materials and methods used experimentally Materials Carboxymethyl-cellulose CM 23 (CM-cellulose) was from Whatman (Kent, UK) and Sephadex G-25 from Pharmacia (Uppsala, Sweden). Trypsin (EC 3.4.21.4) seq. grade, endo- proteinase Lys-C (ERC 3.4.21.50), endoproteinase Asp-N (EC 3.4.24.-) seq. grade and endoproteinase Glu-C (EC 3.4.21.19) from Boehringer Mannheim (Mannheim, FRG). Antibacterial assays Activity was recorded by the inhibition zone assay in thin agarose plates seeded with Escherichia coll strain D21 [Hultmark, D., A. Engstrom, K. Andersson, H. Steiner, H. Bennich and H.G. Boman. 1983. EMBO J. 2: 571-576]. A standard curve was made from known amounts of synthetic cecropin A and 1000 units was defined as an activity equal to that of 1 μg of cecropin A. The chromatographic frac¬ tions were lyophilized and a sample of each fraction was redissolved in 10 μl water and 3 μl was used for each as¬ say. For comparison of activities against different bacte- ria, lethal concentrations (LC values) were calculated from a series of dilutions. LC-values were determined from inhibition zones in plates with LB medium supplemented with Med E (with final concentrations of 0.81 mM MgSO., 9.5 mM citric acid, 57 mM K 2 HP0 4 and 16.7 TH NaNH.HPC ) which increased the activity against E. coli. Strain Bd2221/75 of E. coli is patho. anic for piglets and origina¬ tes from the collection of Olof Sδderlund, SVA, Uppsala, Sweden . Purification The starting material was a concentrate of thermo- stable intestinal peptides, CTIP, prepared from the upper part of the porcine small intestine [Chen, Z.-w., B. Agerberth, K. Gell, M. Andersson, V. Mutt, C.-G. ϋstenson, S. Efendic, J. Barros-Sβderling, B. Persson and H. Jornvall. 1988. Isolation and characterization of porcine diazepam-binding inhibitor, a polypeptide not only of ce¬ rebral occurrence but also common in intestinal tissues, and with effects on regulation of insulin release. [Eur.J.Biochem. 174: 239-245; Mutt, V. 1959. Preparation of highly purified secretin. Ark.Kemi. 15: 69-74], An aqueous solution of CTIP was fractionated with ethanol as described [Lee, J.-Y., A. Boman, S. Chuanxin, M. Andersson, H. Jδrnvall, V. Mutt and H.G. Boman. 1989. Antibacterial peptides from pig intestine: Isolation of a mammalian cecropin. Proc.Natl.Acad. of Sci. USA. 86: 9159- 9162] . The precipitate obtained at -20°C was dissolved in 0.02 M sodium phosphate pH 6.4 and peptides from the solution was adsorbed to CM-cellulose. After washing with 0.2 M NaCl, a peptide fraction was eluted with 0.2 M HC1, the pH of the eluate adjusted to 4 with sodium acetate and peptides precipitated by saturation with NaCl. This precipitate was dissolved in 0.2 M acetic acid and chromatographed on Sephadex G-25 (10 x 150 cm). The eluate corresponding to low molecular weight com¬ ponents was lyophilized before further purificatiaon by reversed-phase HPLC on preparative Vydac 218TP152022 co¬ lumn (22 x 250 mm; The separation Group, Hesperia, CA) and for final purification an analytical Vydac 218TP54 column (4.6 x 250 mm). HPLC chromatography was performed on Waters instruments and absorbance was detected at 214 nm or simultaneously at 214 nm and 280 nm. Structural analysis Purity of the peptides isolated was ascertained by capillary zone electrophoresis with Beckman P/ACE 2000 [Bergman, T., B. Agerberth and H. Jδrnvall. 1991. Direct analysis of peptides and amino acids from capillary elec¬ trophoresis. FEBS lett. 283: 100-103]. Total composition was determined with an LKB 4251 Alpha Plus amino acid ana- lyzer after hydrolysis in evacuated tubes with 6 M HCl/0.5% phenol at 110°C for 22h. Peptides were carboxymetylated with iodoacetamid or iodoacetic acid [Agerberth, B., J. Barros-Sόderling, H. Jϋrnvall, Z.-w. Chen, C.-G. Ostenson, S. Efendic and V. Mutt. 1989. Isolation and characterization of a 60-residue intestinal peptide structurally related to the pancreatic secratory type of trypsin inhibitor: Influence on insulin secretion. Proc.Natl.Acad.Sci. USA. 86: 8590-8594] and desalted on Seppak C18 (Waters, Milford, USA). Carboxyme¬ tylated peptides were cleaved enzymatically with endopro- teinase Asp-N (in 10% acetonitrile/1% NH 4 HC0 3 for 24h at 35°C) and endoproteinase Lys-C (in 1% NH.HCOg for 8h at 37°C) at an enzyme/peptide ratio of 1:20 (w/w) or chemi¬ cally with CNBr in 70% formic acid for 20 hr. Enzymatic digestion of 18 nmol of intact NK-lysine for determination of cysteine-cysteine bridges was performed with trypsin (in 0.1% NH 4 HC0 3 for 6h at 37°C, enzyme/peptide ratio; 1:15 (w/w)) and after HPLC-purification, one fragment was incubated with endoproteinase Glu-C (in 0.5% NH.HCO,, for 16h at 37°C, enzyme/peptide ratio; 1:2 (w/w)). All frag- ments were separated by HPLC on Vydac 218TP54 (4.6 x 250 mm). Edman degradation of intact peptide or fragments thereof were carried out with an ABJ 447 A machine. Pep¬ tide mass was determined using a plasma-desorption time- of-flight mass spectrometer (Biolon 20) or Electrospray analysis performed by Rannar Sillard, Niedersachsisches Institut fur Peptid-Forschung, Hannover, Germany. Computer analyses of the sequences Sequences searches and analyses were performed using the GCG program package (version 7.2) [Devereaux, J., P. Haebrli and 0. Smithies. 1984. Nucleic Acids Res. 12: 387- 395]. EXAMPLE 1 Isolation NK-lysine was isolated from an acid extract of boiled pig intestine. A concentrate of thermostable intestinal pep¬ tides, CTIP, was prepared and after redissolving in water, a peptide fraction obtained on ethanol fractionation and cation-exchange chromatography. The basic fraction (11.4 g) eluted by 0.2 M HC1 was subjected to size exclusion chromatography and the low molecular weight fraction was found to contain antibacterial activity against E. coli and B. Mega erium (Fig. 1A, represented by the bar). In Fig. 1A the basic fraction eluting from CM-cellulose chromatography was dissolved in 0.2 M acetic acid and fractionated by gelfiltration on a Sephadex G-25. The peptides in this fraction were then further sepa¬ rated by repetitive runs on a preparative RP-HPLC column using in acetronitrile/0.1% trifluoroacetic acid as elu- tant (Fig. IB). In Fig. IB peptides eluting as indicated by the bar in (A) were applied to a semipreparativ Vydac 218TP column. The sample was eluted from the column at a flow of 10 ml/min with a linear gradient of 20-50% B in 30 min and then 50-70% B in 5 min (A=0.1% trifluoroacetic acid, B=acetonitrile) . Two main fractions showed high antimicrobial activity against E. coli . Peptides eluting after 220 ml contained a high degree of arginine and proline and was also found to coelute with a recently isolated peptide, PR-39 [Agerberth, B., J.Y. Lee, T. Bergman, M. Carlquist, H.G. Boman, V. Mutt and H. Jδrnvall. 1991. Amino Acid Sequence of PR-39 - Isolation from Pig Intestine of a New Member of the Family of Proline-Arginine-Rich Antibacterial Pepti- des. Eur.J.Biochem. 202: 849-854], when analyzed on capil¬ lary electrophoresis. The peptides eluting at a higher concentration of acetonitrile (300 ml) was subjected to a final purification by analytical reverse-phase HPLC, this time with 0.1% heptafluorobutyric acid in acetontrile as elutant (Fig 1C). In Fig. 1C the relevant fraction was lyophilized and applied to an analytical Vydac 218TP54 co¬ lumn, eluted at 1 ml/min with a linear gradient of 40-60% D in 5 min and then 60-80% D in 30 min (C=0.1% heptafluo- robutyric acid, D=80% acetonitrile/0.1% heptafluorobutyric acid). As can be seen from the figure, two components are separated named NK-lysine (A) and des-Gly-1 NK-lysine (B). The yields were 3.9 mg and 1.2 mg, respectively, after lyophilization. Both peptide eluted as single peaks in capillary zone electrophoresis as shown in Fig. ID. By combining the sequence data from intact peptide and overlapping fragments generated enzymatically or che¬ mically, the entire sequence of 78 amino acids for NK- lysine was obtained (Fig. 2). In this figure the fragmen- tation was made with•cyanobromide (CN1-CN3), Asp-N (Dl- D6) and Lys-C (Kl). II represent intact peptide. Solid lines with arrows show the sequenced regions and dotted lines are fragments in agreement with total amino acid composition. Kl was generated after fragmentation of CN3. Electrospray mass spectrometry measurement yielded a monoisotopic mass of 8923.2±1 which is in good agreement with the molecular mass of 8924.8 calculated from sequence data (assuming that the six cysteines form three intra¬ molecular linkage). Total amino acid analysis was perfor- med on both NK-lysine and des-Gly-1 NK-lysine in their native state and after oxidation by performic acid (Data not shown). Results for NK-lysine were in agreement with sequence data and des-Gly-1 NK-lysine showed a striking similarity to NK-lysine. Mass spectrometry analysis of des-Gly-1 NK-lysine evidenced a monoisotopic mass of 8866.3±1 indicating a difference of 56.9 compared to EC 12, which is identical to the mass of a glycine. Edman degradation of des-Gly-1 NK-lysine identified a peptide identical to des-Gly 1 NK-lysine for the first 18 amino acids. For determination of disulfide linkage, native NK- lysine was enzymatically digested with trypsin and one tryptic fragment thereafter with endoproteinase Glu-C. The products of both digests were purified by HPLC and pepti¬ des containing half-cystein were analysed by sequencer degradation. Results showed that segment S6CRK are asso- ciated with K65PQAICVDIK suggesting a bond between Cys7 and Cys70. Likewise G1YFCE was identified together with 175CKE (cys4-cys76) and L14EDM- together with G43LCK (cys35-cys45). These results are consistent with a di¬ sulfide bridge pattern of Cysl-Cys6, Cys2-Cys5 and Cys3- Cys4 (Fig. 3). In this figure the peptides were aligned with the program PILEUP. Identical amino acids are shown in boxes. Disulfide bridges in NK-lysine are marked by solid lines. EXAMPLE 2 Antibacterial activity We used an inhibition zone assay in agarose gels to test the purified peptides against several strains of bac¬ teria. Both peptides killed Gram-negative and Gram-posi- tive bacteria. The antibacterial spectra as well as the lethal concentrations (the LC-value, the lowest concentra¬ tion that would be lethal for the bacteria) for both pep¬ tides were found to be almost identical (Table 1). High activity was found against E. coli and B. megaterium. There was no activity against Pseudomonas aeruginosa and Staphylococcus aureus, but only a limited number of spe¬ cies were tested. The presence of a high salt concentra¬ tion (with medium E added to the assay plates) increased the activity against E. coli (LC-values decreased about 10 times). A pig pathogenic strain of E. coli (Bd2221/75) was almost 20 times more resistant to NK-lysine than our nor¬ mal assay strain D21 (LC-values were 10 μM compared to 0.54 M). NK-lysine was also found to have antifungal activity and the LC value for Candida albicans was 30 μM, the same as found for defensin, NP-2. Neither peptide gave a lytic zone on sheep red blood cells at a concentration of 170 μM. EXAMPLE 3 Cytotoxicity Since defensins have cytotoxic effects on mammalian cells, we tested NK-lysine also for cytolytic activity against two tumor cell lines known to be sensitive to lysis by NK cells, YAC-1 from mouse and K562 from human. The respective cells were labelled with 51Cr, incubated for different times with NK-lysine (5 μg/ml), with and without fetal calf serum, then the 51Cr released was re¬ corded. Fig. 4 shows that YAC-1 was somewhat more sensi¬ tive than K562, but both cell lines were quite sensitive to NK-lysine. EXAMPLE 4 Computer analysis of the sequence Sequence search in swissprotein database (release 27) with the FASTA program revealed that the NK-lysine showed some homology to two polypeptides, NKG5 and 519, deduced from two cDNA sequences isolated from activated human T and NK cells products [Yabe, T., C. McSherry, F.H. Bach and J.P. Houchins. 1990. A cDNA clone expressed in natural killer and T cells that likely encodes a secreted protein. J.Exp.Med. 172: 1159-1163; Jongstra, J., T.J. Schall, B.J. Dyer, C. Clayberger, J.Jorgensen, M.M. Davis and A.M. Krensky. 1987. The isolation and sequence of a novel gene from a human functional T cell line. J.Exp.Med. 165: 601- 614] . These postulated proteins have 33% identity and 66% similarity when aligned with the program BESTFIT (Fig. 3). Sequences were aligned to NK-lysine with PILEUP and con¬ sensus sequence created by PROFILEMAKE. Similarities to the consensus sequence was searched in EMBL database (release 32) with PROFIELSEARCH. EXAMPLE 5 Nucleotide sequence In Figure 4 there is illustrated the nucleotide sequence of clones corresponding to NK-lysine. The open reading frame corresponding to the peptide is indicated by dotted underlining. The two primers used in the second step of the synthesis (bp 402 to 420 and 565 to 582) are fully underlined, whereas the preliminary probe (bp 532 to 550) is underlined in heavy dots. TABLE 1 Antimicrobial activity of two NK-lvsins from Diα intestine Lethal cone. (μM) for Peptides Bact. and fungal species Strain NK- Ivsin DesGI -NK-lvs. + ed. E -Med. E +Med.E -Med. E Escherichia coli D21 0.5 8 0.8 10 Escherichia coli Bd2221/75 i 10 39 11 40 Pseυdomonas aeruginosa OT97 >190 Nd >160 Nd Acinetobacter Acll 7 Nd 12 Nd calcoaceticus Bacillus megaterium Bmll 1.6 0.8 1.4 0.9 Staphylococcus aureus Cowan 1 Nd >190 Nd >160 Streptococcus pyogenes w.t Nd 34 Nd 30 Candida albicans .t. Nd 31 Nd Nd Lethal concentration is the lowest concentration that will kill the bacteria. Obtained from inhibition zone of a dilution series (Hultmark, D. , A. Engstrδπi, K. Andersson, K. Stei-ier, K. Bennich and H.G. Boman, 1983. EMB0 J. 2: 571-576)

Claims: CLAIMS 1. A polypeptide comprising the following amino acid sequence: GYFCESCRKIIQKLEDMVGPQPNEDTVTQAASQVCDKLKILRGLCKKIMRSFLRRISW DILTGKKPQAICVDIKICKE and functional derivatives and pharmaceutically acceptable salts thereof, said sequence comprising intra-linked half- cysteines. 2. A polypeptide according to claim 1 for therapeutic use. 3. A polypeptide according to claim 2 for use as an antimicrobial agent. 4. A polypeptide according to claim 1 for use based on its lytic activity against NK sensitive tumor cell lines. 5. A polypeptide according to claim 4, wherein said tumor cell lines are of murine or human origin. 6. A pharmaceutical composition containing as an active ingredient the polypeptide according to claim 1 in an effective amount together with a pharmaceutically acceptable carrier or diluent. 7. A pharmaceutical composition according to claim 6, wherein said amount is antimicrobially active. 8. A pharmaceutical composition according to claim 7, wherein said amount is antibacterially active. 9. A pharmaceutical composition according to any of claims 6 to 8, wherein said carrier or diluent is adapted for oral, intravenous, intramuscular or subcutaneous admi¬ nistration. 10. A method for inhibiting microbial growth in ani¬ mals, such as mammals including man, comprising the step of administering to an animal subject to a disorder caused by microbial attack a polypeptide according to claim 1 or a composition according to any of claims 6 to 9 in an in- hibitory amount. 11. A method according to claim 10 for inhibiting bacterial growth. 12. A method for inhibiting tumor cell growth in animals, such as mammals including man, comprising the step of administering to an animal in need of treatment a polypeptide according to claim 1 or a composition accor¬ ding to claim 6 in an inhibitory amount. 13. A method according to claim 10 or 11 for intesti- nal use comprising oral administration of a composition according to any of claims 6 to 9 in a slow release form. 14. A method according to any of claims 10 to 12, comprising administration by injection of a composition according to any of claims 6 to 9 in an injectable dose form. 15. A nucleotide sequence or appropriate fractions thereof as illustrated in Figure 4 of the appended drawings.

Inventors: ANDERSSON MATS, BOMAN HANS G, JOERNVALL HANS, MUTT VIKTOR, ANDERSSON, MATS, BOMAN, HANS, G., JOERNVALL, HANS, MUTT, VIKTOR
Applicants: ANDERSSON MATS, BOMAN HANS G, JOERNVALL HANS, MUTT VIKTOR, ANDERSSON, MATS, BOMAN, HANS, G., JOERNVALL, HANS, MUTT, VIKTOR
Application year: 1995
Main classification: C07K14
IPC codes: A61K38, A61P31, A61P35, C07K14