Chitosan hydrolysis using chitosanolytic enzymes modified with polyalkyleneoxide-maleic anhydride copolymers

A commercially available pectinase which shows chitosanolytic activity was covalently modified with polyalkyleneoxide(PAO)-maleic anhydride(MA) copoly mers, and the effects of modification of enzyme on chitosanolytic character istics, such as initial hydrolysis rate,Michaelis-Menten kinetic parameters , and thermostability, are investigated. Moreover, the time-course of chito san hydrolysis with modified enzymes was obtained experimentally. Enzymatic characteristics change significantly, depending on the hydrophilicity of t he modifier and degree of modification. Even though modification of the enz yme causes a reduction of initial activity in any case, it shows favorable characteristics: an increase in the affinity of enzyme to chitosan, an enha ncement of thermostability, and an improvement of reducing sugar production with long-term hydrolysis. Especially when the enzyme is highly modified w ith a relatively hydrophilic copolymer, AKM-1510, these effect increased si gnificantly.