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Updated: Mar 18, 2026
Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies
Published on: March 6, 2013
Improvement in the thermostability of chitosanase from Bacillus ehimensis by introducing artificial disulfide bonds
Jun Sheng1, Xiaofeng Ji2, Yuan Zheng2
1Laboratory of Enzyme Engineering,Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, People's Republic of China. shengjun@ysfri.ac.cn.
Objective:
To determine the effects of artificial disulfide bridges on the thermostability and catalytic efficiency of chitosanase EAG1.
Results:
Five artificial disulfide bridges were designed based on the structural information derived from the three-dimensional (3-D) model of chitosanase EAG1. Two beneficial mutants (G113C/D116C, A207C-L286C) were located in the flexible surface loop region, whereas the similar substitutions introduced in α-helices regions had a negligible effect. Mut5, the most active mutant, had a longer half-life at 50 °C (from 10.5 to 69.3 min) and a 200 % higher catalytic efficiency (K cat/K m) than that of the original EAG1.
Conclusions:
The contribution of disulfide bridges to enzyme thermostability is mainly dependent on its location within the polypeptide chain. Strategical placement of a disulfide bridge in flexible regions provides a rigid support and creation of a protected microenvironment, which is effective in improving enzyme's thermostability and catalytic efficiency.
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