School of Life Science & Biotechnology, Dalian University of Technology, Dalian, China.
FEMS Microbiol Lett. 2014 Jun;355(1):12-9. doi: 10.1111/1574-6968.12446. Epub 2014 May 13.
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.
植物病原微生物在侵染植物的过程中可以产生果胶甲酯酶（PME）来降解植物细胞壁。这种酶被认为是植物病原物的毒力因子。本研究在毕赤酵母中表达了黄曲霉（Aspergillus flavus）的 PME（AFPME），并进行了体外抑制剂研究。纯化的 AFPME 的产量为 52.2%，SDS-PAGE 显示其为约 40 kDa 的单一条带。该酶的最适活性出现在 55°C 和 pH4.8 的条件下。表没食子儿茶素没食子酸酯（EGCG）强烈抑制重组 AFPME 的活性。分子对接分析表明，EGCG 可以与 AFPME 活性位点中的一些氨基酸残基形成氢键和π-π相互作用。我们的研究为控制黄曲霉的植物入侵提供了一种新策略。
