Peptide mapping of collagen chains using CNBr cleavage of proteins within polyacrylamide gels

A peptide mapping technique is described which uses a two dimensional format to display CNBr peptides of collagen chains. Biosynthetically-labeled products from 250,000 cells are analyzed in each map by a rapid procedure which does not require preliminary purification steps. Proteins trapped within polyacrylamide gels are digested with CNBr under conditions where diffusion of radiolabeled peptides from gels is negligible, and the reaction products are recovered quantitatively by electroelution. Peptide maps of pro alpha chains, alpha chains, and TCA chains cleaved with mammalian collagenase are presented with the identification of specific fragments. This method is useful for the analysis of structural abnormalities in collagen proteins from patients with certain genetic disorders, examination of collagenous proteins produced by primary cultures which exhibit phenotypic switching, and identification of new collagen types.