Recombinant expression and inhibition mechanism analysis of pectin methylesterase from Aspergillus flavus.

Xiuping Jiang, Qiulei Jia, Lei Chen, Qi Chen, Qing Yang

Index: FEMS Microbiol. Lett. 355(1) , 12-9, (2014)

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Abstract

Phytopathogenic microorganisms can produce pectin methylesterase (PME) to degrade plant cell walls during plant invasion. This enzyme is thought to be a virulence factor of phytopathogens. In this work, PME from Aspergillus flavus (AFPME) was expressed in Pichia pastoris and an in vitro inhibitor study was performed. The purified AFPME with a yield of 52.2% was resolved as one band with a molecular mass of c. 40 kDa by SDS-PAGE. Optimal activity of the enzyme occurred at a temperature of 55 °C and a pH of 4.8. Epigallocatechin gallate (EGCG) strongly inhibited the activity of recombinant AFPME. The molecular docking analysis indicated that EGCG could form hydrogen bonds and π-π interactions with some amino acid residues in the active site of AFPME. Our studies provide a novel strategy for the control of the plant invasion of A. flavus. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.