Molecular parameters of chitosans depolymerized with the aid of papain

The profiles and positions of the GPC curves are progressively altered during the course of the papain-promoted hydrolysis of chitosan. The chitosan fractions having the highest degrees of polymerization are depolymerized and Mw, [eta] and R(G) values are lowered. Viscometric measurements confirm that the immobilized papain depolymerizes chitosan with high initial velocity, the more acetylated chitosan [0.42] being more susceptible to papain than chitosan [0.22] and chitosan [0.15]. This holds true for chemically reacetylated chitosan [0.49] as well. The behavior of papain in this respect is different from that of lysozyme which is more active on chitosan [0.22] than on more acetylated chitosans. The data suggest that papain acts on the link between glucosamine and N-acetylglucosamine units. Copyright (C) 1996 Elsevier Science Ltd