Identification of biologically active sequences in the laminin α2 chain G domain

Laminin α2 chain is specifically expressed in the basement membrane surrounding muscle and nerve. We screened biologically active sequences in the mouse laminin α2 chain G domain using 110 soluble peptides by the peptide-coated plate and the peptide-conjugated Sepharose bead assays. Fourteen peptides showed cell attachment activity in either or both assays. Cell attachment to A2G94 (YFDGTGFAKAVG) was inhibited by anti-integrin β1 antibody, suggesting that the peptide promotes an integrin β1-mediated cell attachment. Five peptides promoted PC12 cell neurite outgrowth. Since A2G10 (SYWYRIEASRTG) promoted strong cell attachment in the bead assay but showed slight activity in the plate assay, we conjugated A2G10 to chitosan membranes which increase cell attachment activity of the peptides via conformational stability. A2G10–chitosan membrane promoted an integrin α6β1-mediated cell attachment and spreading with well-organized actin stress fibers and neurite outgrowth. These active peptides are useful for evaluating the molecular mechanisms of laminin–receptor interactions.