Patent ID: 7132393

Claim:
A transporter composition for transporting a moiety into cells in acidic areas of a tumor, wherein said transporter composition comprises (a) a transporter peptide which is poly-anionic at pH 7.2 and above, and that converts to a lipophilic form effective to transport into cells at a pH below 7.2 that is present in acidic areas of a tumor, said transporter peptide containing (xi) a peptide sequence ranging in length from about 16 to about 50 amino acids, (xii) wherein said peptide sequence contains at least three acid pairs, where said acid pairs except for the acid pair closest to the entry end are selected from the group consisting of EE, ELLE, and ELLLE, (xiii) each acid of the acid pairs of said peptide sequence except for the acid closest to the entry end is a side chain carboxyl of glutamic acid, (xiv) the acid closest to the entry end is selected from the group consisting of a side chain carboxyl of glutamic acid and another carboxyl-containing side chain effective to form an acid pair with a nearby glutamic acid side chain, (xv) the number of acid side chains in the core transporter peptide sequence of said peptide sequence is less than 40% of the total side chains in the core transporter peptide sequence, (xvi) in said peptide sequence the axial center point of one acid pair relative to the axial center point of the adjacent acid pair along the alpha-helical peptide backbone is rotated by a number of degrees selected from the group consisting of 450, 500, 550, 600, and 650 degrees, except for the rotation between an EE acid pair and an ELLE acid pair which is 700 degrees, and the rotation between an EE acid pair and an ELLLE acid pair which is 750 degrees, (xvii) the average of the axial rotations between acid pairs in said peptide sequence is greater than 500 degrees, wherein ‘L’ is a lipophilic amino acid selected from the group consisting of leucine, isoleucine, norleucine and methionine, (xviii) at least 90% of the non-acid side chain amino acids of said peptide sequence are lipophilic amino acids (L) selected from the group consisting of leucine, isoleucine, norleucine and methionine, (xix) the entry end of said peptide sequence is predominantly non-ionic at a pH that is present in acidic areas of a tumor, (xx) at least 90% of the amino acids of said peptide sequence are of the same chirality; and, (b) a cargo component which can be pulled across a cell membrane by the transporter peptide, and which contains at least one moiety selected from the group consisting of a diagnostic moiety and a therapeutic moiety.