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Thermostability and Specific-Activity Enhancement of an Arginine Deiminase from Enterococcus faecalisSK23.001 via Semirational Design for l-Citrulline Production

Thermostability and Specific-Activity Enhancement of an Arginine Deiminase from Enterococcus faecalisSK23.001 via Semirational Design for l-Citrulline Production

Authors :
Cai, Xue
Jiang, Hangyu
Zhang, Tao
Jiang, Bo
Mu, Wanmeng
Miao, Ming
Source :
Journal of Agricultural and Food Chemistry; July 2018, Vol. 66 Issue: 33 p8841-8850, 10p
Publication Year :
2018

Abstract

l-Citrulline is a nonessential amino acid with a variety of physiological functions and can be enzymatically produced by arginine deiminase (ADI, EC 3.5.3.6). The enzymatic-production approach is of immense interest because of its mild conditions, high yield, low cost, and environmental benignity. However, the major hindrances of l-citrulline industrialization are the poor thermostability and enzyme activity of ADI. Hence, in this work, directed evolution and site-directed mutagenesis aided with in silico screening, including the use of b-factor values and HoTMuSiC, were applied to a previously identified ADI from Enterococcus faecalisSK23.001 (EfADI), and a triple-site variant R15K–F269Y–G292P was obtained. The triple-site variant displays a 2.5-fold higher specific enzyme activity (333 U mg–1), a lower Kmvalue of 6.4 mM, and a 6.1-fold longer half-life (t1/2,45°C= 86.7 min) than wild-type EfADI. This work provides a protein-engineering strategy to improve enzyme activity and thermostability, which might be transferrable to other ADIs and enzymes.

Details

Language :
English
ISSN :
00218561 and 15205118
Volume :
66
Issue :
33
Database :
Supplemental Index
Journal :
Journal of Agricultural and Food Chemistry
Publication Type :
Periodical
Accession number :
ejs46098104
Full Text :
https://doi.org/10.1021/acs.jafc.8b02858