Mutation of Trp137 to glutamate completely removes transglycosyl activity associated with the Aspergillus fumigatus AfChiB1 | |
Lue, Yang ; Yang, Haitao ; Hu, Hongyan ; Wang, Ying ; Rao, Zihe ; Jin, Cheng | |
2010-10-12 ; 2010-10-12 | |
关键词 | Chitinase Transglycosylation Aspergillus fumigatus Mutation SUBSTRATE-ASSISTED CATALYSIS HUMAN MACROPHAGE CHITINASE NOCARDIA-ORIENTALIS GLYCOSYL HYDROLASE CRYSTAL-STRUCTURES ALLOSAMIDIN LYSOZYME COMPLEX CHITOTRIOSIDASE HYDROLYSIS Biochemistry & Molecular Biology |
中文摘要 | Family 18 chitinases hydrolyze chitin through a substrate-assisted catalytic mechanism and are to a variable extent able to catalyze transglycosylation reactions. Previously Aspergillus fumigatus AfChiB1 was found to be able to catalyze transglycosylation reactions. Structural analysis reveals that AfChiB1 consists of an eight-stranded beta/alpha-barrel. Like other members of the family 18 hydrolases, AfChiB1 has conserved substrate binding site and catalytic acid, while a suitable nucleophile is missing. In this study, Trp137, Asp246, and Met243, which are close to the glycosidic cleavage site, were mutated to glutamate individually. As a result, the W137E remained its hydrolytic activity and was completely devoid of transglycosyl activity, while the D246E reduced its chitinolytic activity and increased its transglycosyl activity. And the M243E showed a remarkable reduction of chitinolytic activity and complete loss of transglycosyl activity. These results suggested that the transglycosyl reaction catalyzed by the AfChiB1 is due to lacking of nucleophile. |
语种 | 英语 ; 英语 |
出版者 | SPRINGER ; DORDRECHT ; VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS |
内容类型 | 期刊论文 |
源URL | [http://hdl.handle.net/123456789/81835] |
专题 | 清华大学 |
推荐引用方式 GB/T 7714 | Lue, Yang,Yang, Haitao,Hu, Hongyan,et al. Mutation of Trp137 to glutamate completely removes transglycosyl activity associated with the Aspergillus fumigatus AfChiB1[J],2010, 2010. |
APA | Lue, Yang,Yang, Haitao,Hu, Hongyan,Wang, Ying,Rao, Zihe,&Jin, Cheng.(2010).Mutation of Trp137 to glutamate completely removes transglycosyl activity associated with the Aspergillus fumigatus AfChiB1.. |
MLA | Lue, Yang,et al."Mutation of Trp137 to glutamate completely removes transglycosyl activity associated with the Aspergillus fumigatus AfChiB1".(2010). |
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