| Literature DB >> 1567379 |
M P Romaniec1, U Fauth, T Kobayashi, N S Huskisson, P J Barker, A L Demain.
Abstract
An endoglucanase (1,4-beta-D-glucan glucanohydrolase, EC 3.2.1.4) from the thermophilic anaerobe Clostridium thermocellum was purified to apparent homogeneity without the use of denaturants. No carbohydrate is associated with the endoglucanase. A molecular mass of 76,000 Da was determined by SDS/PAGE. The optimal pH is 7.0 and the enzyme is isoelectric at pH 5.05. The enzyme has a temperature optimum of 70 degrees C and retains approx. 50% of its activity after 48 h at 60 degrees C. Hydrolysis of CM-cellulose takes place with a rapid decrease in viscosity but a slow liberation of reducing sugars, indicating an endoglucanase type of activity. The endoglucanase shows little ability to hydrolyse highly ordered cellulose. Cellobiose inhibits whereas Mg2+ and Ca2+ stimulate the activity. The enzyme is completely inactivated by 1 mM-Hg2+ and is inhibited by a thiol-blocking reagent.Entities:
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Year: 1992 PMID： 1567379 PMCID： PMC1130994 DOI： 10.1042/bj2830069
Source DB: PubMed Journal: Biochem J ISSN： 0264-6021 Impact factor: 3.857