Structural analogies between adhesive proteins and cysteine proteinase inhibitors

Structural analogies were found between adhesive proteins, fibronectin and laminin, and a group of cysteine proteinase inhibitors. The sequences analogous with inhibitors occur in both adhesive molecules in the vicinity of their cell-binding sites: they comprise residues 1112-1212 in fibronectin and residues 1538-1639 of B1 chain in laminin. Both adhesive molecules display the highest degree of analogy with stefin-type inhibitors. The structural analogies also exist between fibronectin, laminin and P21, the c-Ha-ras gene protein produced by Escherichia coli.