Back to Search Start Over

Enhanced catalytic efficiency and thermostability of glucose isomerase from Thermoanaerobacter ethanolicus via site-directed mutagenesis.

Authors :
Jin LQ
Jin YT
Zhang JW
Liu ZQ
Zheng YG
Source :
Enzyme and microbial technology [Enzyme Microb Technol] 2021 Dec; Vol. 152, pp. 109931. Date of Electronic Publication: 2021 Oct 06.
Publication Year :
2021

Abstract

Glucose isomerase (GI) is a key enzyme in the preparation of high fructose corn syrup (HFCS). In this study, a mutant TEGI-M-L38 M/V137 L (TEGI-M2) of glucose isomerase (TEGI-M) originated from Thermoanaerobacter ethanalicus CCSD1 was obtained by site-directed mutagenesis. The TEGI-M2 showed an optimal activity at 85 ℃ and pH 6.5 with the divalent cations Co <superscript>2+</superscript> and Mg <superscript>2+</superscript> . The structural differences between TEGI-M and TEGI-M2 were investigated based on the homology modeling and molecular docking, to elucidate the mechanism of improvement in the enzymatic properties. Compared with the original enzyme, the TEGI-M2 showed a 2.0-fold increased enzyme activity and a decreased K <subscript>m</subscript> from 234.2 mM to 85.9 mM. Finally, the application of mutant TEGI-M2 in HFCS one-step biosynthesis was attempted, resulting in a d-fructose yield of 67.3 %, which was 14.3 % higher than that of TEGI-M. This improved catalytic performance of TEGI-M2 was of great importance for the industrial preparation of d-fructose in one-step process.<br /> (Copyright © 2021 Elsevier Inc. All rights reserved.)

Details

Language :
English
ISSN :
1879-0909
Volume :
152
Database :
MEDLINE
Journal :
Enzyme and microbial technology
Publication Type :
Academic Journal
Accession number :
34688091
Full Text :
https://doi.org/10.1016/j.enzmictec.2021.109931