The all-D-configuration segment containing the IKVAV sequence of laminin A chain has similar activities to the all-L-peptide in vitro and in vivo.
Laminin is a basement membrane glycoprotein that has diverse biological activities. A sequence on the A chain containing IKVAV (Ile-Lys-Val-Ala-Val) has been shown to promote neurite outgrowth, cell adhesion, and tumor growth and metastasis. Here we have determined the structural requirements of this synthetic peptide for biological activity. Twelve-amino acid-long all-L- (LAM-L) and all-D-peptide (LAM-D) segments as well as an alternating D- and L-amino acid-containing peptide (LAM-DL), which included the IKVAV sequence (residues 2097-2108), were synthesized. Circular dichroism spectral analysis revealed a mirror image conformation of LAM-D and LAM-L with mainly beta-sheet and to a minor extent alpha-helical structure. LAM-DL did not exhibit any significant ordered conformational features. LAM-D and LAM-L showed similar cell attachment activities for rat pheochromocytoma cells (PC12), whereas LAM-DL was inactive. A peptide analog with randomized IKVAV sequence (LAM-RM) was also inactive. A similar trend was observed in competition experiments of the four peptides with laminin in analogous cell attachment assays. In in vivo experiments, both LAM-D and LAM-L were capable of increasing tumor growth when subcutaneously injected into mice with murine melanoma cells B16F10. Results indicate that the conformational status of the IKVAV domain is a contributing factor in determining the biological activity but that there is no strict requirement for a specific chirality. There is a likely sequence specificity to the IKVAV region.
Nomizu
M
M
Laboratory of Medicinal Chemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Utani
A
A
Shiraishi
N
N
Kibbey
M C
MC
Yamada
Y
Y
Roller
P P
PP
D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002942:Circular Dichroism; D007700:Kinetics; D007797:Laminin / Q000737:chemistry* / Q000494:pharmacology; D046911:Macromolecular Substances; D008546:Melanoma, Experimental / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016716:PC12 Cells; D010446:Peptide Fragments / Q000737:chemistry* / Q000494:pharmacology; D010455:Peptides / Q000138:chemical synthesis* / Q000494:pharmacology; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D007797:Laminin; D046911:Macromolecular Substances; D010446:Peptide Fragments; D010455:Peptides