Amino Acids and Peptides. XXVI. Laminin-Related Peptide Poly (Ethylene Glycol) Hybrids and Their Inhibitory Effect on Experimental Metastasis

Laminin-related peptide poly (ethylene glycol) hybrid, Tyr-Ile-Gly-Ser-Arg-aminopoly (ethylene glycol) was prepared by the solution method and carboxylated poly (ethylene glycol)-Tyr-Ile-Gly-Ser-Arg was prepared by the solid phase method. Their inhibitory effects on experimental tumor metastasis were examined in mice. The inhibitory effect of Tyr-Ile-Gly-Ser-Arg was significantly potentiated by hybrid formation with poly (ethylene glycol) either at amino- or carboxyl terminals of the peptide. Of the hybrids, Tyr-Ile-Gly-Ser-Arg-amino (polyethylene glycol) #6000 hybrid exhibited about 10 times more potent anti-metastatic effect than the peptide itself. The inhibitory effect of a mixture of the carboxylated poly (ethylene glycol) hybrid and Arg-Gly-Asp-aminopoly (ethylene glycol) hybrid also exhibited an inhibitory effect.