Analysis of the heterogeneity of human collagens by two-dimensional polyacrylamide-gel electrophoresis

Abstract

The heterogeneity of the CNBr-cleavage peptides of human types I, II, III and V collagens were studied by using two-dimensional electrophoresis combining nonequilibrium pH-gradient-gel electrophoresis and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Specific 'maps' were produced by the peptides obtained from the chains of each type of collagen, and most peptides had at least three charged forms of the same molecular weight. Specific 'maps' were also produced by the peptides of types I, III and V collagens from insoluble dermis and the peptides of types I and V collagens from decalcified bone. The α1 (I) CB7 and α1 (I) CB8 and the α2 CB4 peptides obtained from the type I collagens of these tissues contained the same number of charged components, but there was a relative increase in the more basic components in bone. Some aspects of the involvement of the α1 (I) CB6 and the α1 (III) CB9 peptides in cross-linkages were also studied. The recovery of the α1 (I) CB6 peptide from bone and dermis was decreased and the α1 (III) CB9 peptide was not detected in dermis. Additional peptides, which were probably cross-linked peptides involving the α1 (I) CB6 peptide, were also observed.