Enzymatic activity of PEOMA-modified lysozyme obtained from degradation of Micrococcus luteus cell and N-acetylated chitosan

摘要

A chicken egg white lysozyme was modified with a polyethyleneoxide-maleic anhydride (PEOMA) copolymer and two types of substrates, Micrococcus luteus (ML) cell walls and N-acetylated chitosan (NAC), which were used to determine the enzymatic activity of the PEOMA-modified lysozymes with a different degree of modification (DM). The ML cell walls and NAC were used as the substrates in their heterogeneous and homogeneous states, respectively. Modified lysozymes whose DM values ranged from 0 to 70% were used for both substrates. The enzymatic activity of the PEOMA-modified lysozyme drastically decreassed at a DM from 40 to 50% in both cases, and an identical relationship between the enzymatic activity and the DM were observed. From these results, it is obvious that the enzymatic activity of PEOMA-modified lysozymes can be determined by using the two substrates, without considering the state of the substrate.