%0 Journal Article
%T Domain-swapping of mesophilic xylanase with hyper-thermophilic glucanase
%A Liangwei Liu
%A Linmin Wang
%A Zhang Zhang
%A Xiaodan Guo
%A Xiangqian Li
%A Hongge Chen
%J BMC Biotechnology
%D 2012
%I BioMed Central
%R 10.1186/1472-6750-12-28
%X When expressed in E. coli BL21(DE3), the two chimeras exhibited bi-functional activities of xylanase and glucanase. The Xyn-Glu Xyn moiety had optimal reaction temperature (Topt) at 50£¿¡ãC and thermal in-activation half-life (t1/2) at 50£¿¡ãC for 47.6£¿min, compared to 47£¿¡ãC and 17.6£¿min for the Xyn. The Glu-Xyn Xyn moiety had equivalent Topt to and shorter t1/2 (5.2£¿min) than the Xyn. Both chimera Glu moieties were more thermostable than the Glu, and the three enzyme Topt values were higher than 96£¿¡ãC. The Glu-Xyn Glu moiety optimal pH was 5.8, compared to 3.8 for the Xyn-Glu Glu moiety and the Glu. Both chimera two moieties cooperated with each other in degrading substrates.Domain-swapping created different effects on each moiety properties. Fusing the Glu domain at C-terminus increased the xylanase thermostability, but fusing the Glu domain at N-terminus decreased the xylanase thermostability. Fusing the Xyn domain at either terminus increased the glucanase thermostability, and fusing the Xyn domain at C-terminus shifted the glucanase pH property 2 units higher towards alkaline environments. Fusing a domain at C-terminus contributes more to enzyme catalytic activity; whereas, fusing a bigger domain at N-terminus disturbs enzyme substrate binding affinity.
%K Xylanase
%K Glucanase
%K Domain-swapping
%K Fusing
%U http://www.biomedcentral.com/1472-6750/12/28/abstract