Characterization of CenC, an enzyme from Cellulomonas fimi with both endo- and exoglucanase activities.

摘要: The cenC gene, encoding beta-1,4-glucanase C (CenC) from Cellulomonas fimi, was overexpressed in Escherichia coli with a tac-based expression vector. resulting polypeptide, an apparent molecular mass of 130 kDa, purified the cell extracts by affinity chromatography on cellulose followed anion-exchange chromatography. N-terminal sequence analysis showed enzyme to be properly processed. Mature CenC optimally active at pH 5.0 and 45 degrees C. extremely soluble, fluorophoric, chromophoric glycosides (4-methylumbelliferyl beta-glycosides, 2'-chloro-4'-nitrophenyl-beta-D-cellobioside, 2'-chloro-4'-nitrophenyl-lactoside) efficiently hydrolyzed carboxymethyl cellulose, barley beta-glucan, lichenan, and, lesser extent, glucomannan. also acid-swollen Avicel, bacterial microcrystalline cellulose. However, degradation latter slow compared its CenB, another fimi belonging same family. acted inversion configuration anomeric carbon, accordance classification as family 9 member. released mainly cellobiose soluble cellodextrins insoluble Attack appeared reducing chain ends. Analysis hydrolysis suggests that is semiprocessive both endo- exoglucanase activities.