Chemical and Enzymatic Modifications of Collagen: The Effect of Cross‐linking on the Enzyme‐binding Capacity of Collagen

The effect of structural modifications on the enzyme‐binding capacity of collagen has been studied using p‐galactosidase ( E. coli K 1 2) immobilized to collagen membranes. The immobilization process employs simple and inexpensive techniques to bind the enzyme to collagen through direct protein‐protein interaction. The tertiary structure of the collagen matrix was modified by cross‐linking with the difunctional reagent, glutaraldehyde, or by a natural cross‐linking process associated with aging. Such modifications were found to markedly reduce the enzyme (β‐galactosidase)‐binding capacity of collagen films. The deleterious effect of cross‐linking on the binding capacity of collagen was shown to be completely reversed by proteolytic enzyme treatment of aged films but only partly so for glutaraldehyde‐treated films.