A mycelial chitin deacetylase has been purified from a chitin deacetylase-hyperproducing fungus, Absidiα coerulea CHK-1. The purified enzyme had a molecular mass of about 62 kDa on denaturated and natural conditions. The pI was 5.5. The chitin deacet...
A mycelial chitin deacetylase has been purified from a chitin deacetylase-hyperproducing fungus, Absidiα coerulea CHK-1. The purified enzyme had a molecular mass of about 62 kDa on denaturated and natural conditions. The pI was 5.5. The chitin deacetylase, when resolved by SDS-PAGE, was positive for Schiff staining, suggesting that the enzyme is a glycoprotein. When O-hydroxylated chitin (glycolchitin) was used as a substrate, the enzyme displayed a temperature optimum of around 50℃ and a pH optimum of around PH 5,5. The enzyme was stable to incubation from pH 3.0 to pH 6.5 at 4℃ for 24 hr. The presence of chitin protected the enzyme from heat inactivation, the extent depending upon the substrate concentration. The activity of the enzyme was stimulated by Mn2+ ion. The enzyme is active on chitooligosaccharides with more than two N-acetylglucosamine residues (M-acetylchitobiose). However, the enzyme is not active on N-acetylglucosamine. The enzyme had an apparent Km of 12.4 mM and Kcat of 32.4 /sec for glycol chitin, respectively.