Rationally engineered chitin deacetylase from Arthrobacter sp. AW19M34-1 with improved catalytic activity toward crystalline chitin

Zhiwen Ding; Sibtain Ahmed; Jiahao Hang; Haoyu Mi; Xiaoyue Hou; Guang Yang; Zhifa Huang; Xiaoyue Lu; Wei Zhang; Shu Liu; Yaowei Fang

doi:10.1016/j.carbpol.2021.118637

Rationally engineered chitin deacetylase from Arthrobacter sp. AW19M34-1 with improved catalytic activity toward crystalline chitin

Carbohydr Polym. 2021 Nov 15:274:118637. doi: 10.1016/j.carbpol.2021.118637. Epub 2021 Sep 8.

Authors

Zhiwen Ding¹, Sibtain Ahmed², Jiahao Hang¹, Haoyu Mi¹, Xiaoyue Hou¹, Guang Yang¹, Zhifa Huang¹, Xiaoyue Lu³, Wei Zhang¹, Shu Liu⁴, Yaowei Fang⁵

Affiliations

¹ Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
² Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA.
³ Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China.
⁴ Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; School of Food Science and Engineering, Jiangsu Ocean University, Lianyungang 222005, China.
⁵ Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; School of Food Science and Engineering, Jiangsu Ocean University, Lianyungang 222005, China; Jiangsu Marine Resources Development Research Institute, Jiangsu Ocean University, Lianyungang 222000, China. Electronic address: foroei@163.com.

PMID: 34702460
DOI: 10.1016/j.carbpol.2021.118637

Abstract

Chitin and its derivatives have anticoagulant, antimicrobial, and antioxidant properties, but the poor solubility of chitin limits its application in different fields. In this study, site-directed mutagenesis was performed to enhance the deacetylation activity of chitin deacetylases CDA from Arthrobacter (ArCE4). The mutant Mut-2-8 with Y172E/E200S/Y201W showed a 2.84- fold and 1.39-fold increase in catalytic efficiency (kcat/Km) for the deacetylation of (GluNAc)₅ and α-chitin, respectively. These results demonstrated that the mutations significantly improved the activation of ArCE4 on crystalline chitin. The molecular docking study confirmed that the enhancement of catalytic efficiency is due to the extra two hydrogen bonds and one acetyl group. In summary, the activity of Mut-2-8 to insoluble chitin was significantly improved by reactional design, which is beneficial to resolve the issues of the expensive cost of the enzymes and low efficiency. Mut-2-8 exhibits potential applications in the chitosan industry.

Keywords: Chitin deacetylase; Chitosan; Crystalline chitin; Rational design.

MeSH terms

Amidohydrolases / chemistry*
Arthrobacter / metabolism*
Chitin / chemistry*
Kinetics

Substances

Chitin
Amidohydrolases
chitin deacetylase