Active peptides from the carboxyl-terminal globular domain of laminin alpha2 and Drosophila alpha chains

The laminin alpha1 chain carboxyl-terminal globular domain (G domain) contains multiple biological activities. Recently, we identified five cell binding sequences from the G domain by screening with overlapping 12-mer peptides encompassing the entire domain. The structures of these five sequences in the alpha1 chain are conserved in the corresponding regions of the different laminin alpha chains. Here we characterize the adhesion activities of the corresponding peptide segments from both the mouse laminin alpha2 chain and Drosophila laminin alpha chain using peptide-coated plastic plates and peptide-conjugated Sepharose beads. Using several cell lines, the laminin alpha2 chain peptides showed cell attachment and/or spreading activities with cell type specificities. Cell spreading on MG-10 was inhibited by integrin antibodies. Four of the Drosophila laminin peptides showed cell attachment activities. These results suggest that biologically active regions in the G domain are conserved in the laminin alpha1 and alpha2 chains, and that these regions in laminin play an important role in cell surface receptor interactions.