Relationship between laminin peptides and integrin alpha 1,alpha 2,alpha 3,alpha 5 and beta 1.

We synthesized several peptides according to a hypothesis that a similar motif of peptide containing four hydrophobic and one hydrophilic amino acids mediate cell attachment and neurite outgrowth, and we have detected six active peptides derived from the alpha 1 (A) chain of laminin-1 (EHS laminin). Furthermore, we snythesized YP-14 and YP-15 derived from the sequence of NCAM and rabbit actin, respectively, and detected these peptides to be active for cell attachment and neurite outgrowth. When the activity of peptide IKVAV (10 mu g/well coated) for cell attachment and neurite outgrowth was taken as 100%, the cell attachment activity of both YP-14 and YP-15 showed about 80%. The neurite outgrowth activity of YP-14 showed about 50%, and that of YP-15 showed about 90% in 10 mu g/well coated each peptide. We studied relationship between eight active peptides and integrins using the inhibition assay of cell attachment with anti-integrin alpha 1, alpha 2, alpha 3, alpha 5 and beta 1 antibody. Anti-integrin alpha 1 antibody did not inhibit, while anti-alpha 2 antibody inhibited activity of IKVAV, IKLLI, YFQRYLI, AG-6, YP-11 and YF-15. Anti-alpha 3 antibody inhibited that of IKLLI, anti-alpha 5 antibody inhibited that of IKLLI, AG-6 and YP-15. Anti-beta 1 antibody inhibited that of IKLLI and YFQRYLI. The results showed that IKLLI may relate with VLA-2 (alpha 2 beta 1), VLA-3 (alpha 3 beta 1), VLA-5 (alpha 5 beta 1) and YFQRYLI may relate with VLA-2 (alpha 2 beta 1).