Cross-linking of fibronectin to collagenous proteins

Attempts were made to cross-link several collagenous proteins to fibronectin with Factor XIIIa (plasma transglutaminase). Cross-linking was demonstrated with type I collagen, type II collagen, type III collagen, type V or AB collagen, and alpha 1(I)-CB7 and alpha 1(I)-CB8 cyanogen bromide fragments of type I collagen. Cross-linking was not demonstrated with type IV collagen, Clq, and cyanogen bromide fragment alpha 1(I)-CB6. The pH optimum for cross-linking of alpha 1(I)-CB7 to fibronectin was 8.5 to 9.6. Cross-linking of alpha 1(I)-CB7 to fibronectin was somewhat enhanced at lower than physiological ionic strength.