标题:Expression and characteristics of a Ca2+-dependent endoglucanase from Cytophaga hutchinsonii
作者:Zhang, Cong; Zhang, Weican; Lu, Xuemei
作者机构:[Zhang, Cong; Zhang, Weican; Lu, Xuemei] Shandong Univ, Coll Life Sci, State Key Lab Microbial Technol, Jinan 250100, Peoples R China.
通讯作者:Lu, Xuemei
通讯作者地址:[Lu, XM]Shandong Univ, Coll Life Sci, State Key Lab Microbial Technol, Jinan 250100, Peoples R China.
来源:APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
出版年:2015
卷:99
期:22
页码:9617-9623
DOI:10.1007/s00253-015-6746-3
关键词:Cytophaga hutchinsonii; Family 9 glycoside hydrolase; Endoglucanase;; Calcium-dependent
摘要:Cytophaga hutchinsonii is a Gram-negative bacterium that can degrade crystalline cellulose efficiently with an unknown strategy. Genomic analysis suggested it lacks exoglucanases which are found in many cellulolytic organisms and most of the cellulases in C. hutchinsonii lack recognizable carbohydrate-binding modules (CBMs). CHU_1280, speculated to be an endoglucanase belonging to glycoside hydrolase family 9 (GH9) in C. hutchinsonii, was functionally expressed in Escherichia coli, and evidence was presented suggesting that it may be a processive endoglucanase. In the absence of Ca2+, CHU_1280 was inactive. But in the presence of Ca2+, it had a specific activity of 600 U/mu mol with carboxymethyl cellulose (CMC) as the substrate. With Ca2+, CHU_1280 hydrolyzed regenerated amorphous cellulose (RAC) with nearly 80 % of the reducing ends appearing in the soluble fraction, suggesting it degraded cellulose in a processive way. CHU_1280 could bind to cellulose without recognizable CBMs and its binding ability was also Ca2+-dependent. Ca2+ could stabilize the catalytic domain at high temperature, but the denaturation temperature of the whole protein was decreased. C. hutchinsonii might have an exoglucanase-independent cellulases system which included endoglucanases, processive endoglucanases, and beta-glucosidases.
收录类别:EI;SCOPUS;SCIE
WOS核心被引频次:9
Scopus被引频次:9
资源类型:期刊论文
原文链接:https://www.scopus.com/inward/record.uri?eid=2-s2.0-84945924080&doi=10.1007%2fs00253-015-6746-3&partnerID=40&md5=8f3416e8c9274c5ad6c750e33eef8cb5
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