| Literature DB >> 4218236 |
Abstract
An enzyme that has both beta-1,4-glucanase and chitosanase activities is characterized. Evidence for homogeneity was obtained from electrophoresis and sedimentation velocity studies; only one N-terminal amino acid, valine, was found. Results of denaturation studies showed that beta-1,4-glucanase and chitosanase activities decreased at equal rates. With carboxymethylcellulose as the substrate, a K(m) of 1.68 g of carboxymethylcellulose per liter of solution and a V(max) of 2.20 x 10(-9) mol/min were found. With chitosan (the beta-1,4-polymer of glucosamine) as the substrate, a K(m) of 0.30 g of chitosan per liter of solution and a V(max) of 0.75 x 10(-9) mol/min were found. A pH optimum of 5.0 was found for beta-1,4-glucanase activity, and pH optima of 5.0 and 6.8 were found for chitosanase activity. beta-1,4-Glucanase activity had a temperature optimum of 38 C, and chitosanase activity had a temperature optimum of 70 C. Chitosan stabilized both enzyme activities at 70 C. Cellotriose was the smallest polymer capable of hydrolysis. Glucosamine was released by action of the enzyme upon cell wall preparations of several fungi.Entities:
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Year: 1974 PMID: 4218236 PMCID: PMC245847 DOI: 10.1128/jb.120.2.844-853.1974
Source DB: PubMed Journal: J Bacteriol ISSN: 0021-9193 Impact factor: 3.490