title: Characterization of the endoglucanase and glucomannanase activities of a glycoside hydrolase family 45 protein from Penicillium decumbens 114-2.
abstract: The gene encoding a glycoside hydrolase (GH) family 45 endoglucanase (Cel45A) was cloned from P. decumbens 114-2 and expressed in Pichia pastoris. To our knowledge, this is the first report of characterization of a GH family 45 protein from Penicillium species. The purified recombinant enzyme showed a higher activity on konjac glucomannan (KGM) than on sodium carboxymethyl cellulose (CMC-Na) or phosphoric acid swollen cellulose (PASC). The highest hydrolytic activity was detected at pH5.0 on KGM and pH 3.5 on CMC-Na, indicating the mode of action on the two substrates may be different for Cel45A. The optimum temperatures on the two substrates were both 60 degrees C and about 90% relative activities were retained at 70 degrees C. Products released from PASC and CMC-Na were mainly cellobiose, cellotriose and cellotetraose. The protein with higher glucomannanase activity might help the efficient degradation of lignocellulose by P. decumbens in the natural state.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong, P.R. China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Liu
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Wei
authors.forename: Yuqi
authors.initials: Y
authors.lastname: Qin
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Qu
mesh_terms: D000595:Amino Acid Sequence; D002480:Cellulase / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008351:Mannans / Q000378:metabolism*; D008969:Molecular Sequence Data; D010407:Penicillium / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D008351:Mannans; C022901:(1-6)-alpha-glucomannan; D006026:Glycoside Hydrolases; D002480:Cellulase