Purification and biochemical characterization of FrsA protein from Vibrio vulnificus as an esterase

PLoS One. 2019 Apr 5;14(4):e0215084. doi: 10.1371/journal.pone.0215084. eCollection 2019.

Abstract

Fermentation-respiration switch protein (FrsA) was thought to play an important role in controlling the metabolic flux between respiration and fermentation pathways, whereas the biochemical function of FrsA was unclear yet. A gene coding for FrsA protein from Vibrio vulnificus was chemically synthesized. The recombinant VvFrsA was expressed as a soluble protein and purified by Ni-NTA affinity chromatography. The protein had a subunit molecular weight of ca. 45 kDa by SDS-PAGE and preferred short-chain esters when p-nitrophenyl alkanoate esters were used as substrates. Optimum condition for VvFrsA was found to be at pH 9.0 and 50 °C. The protein retained high esterase activity at alkaline condition and would denature slowly at over 50 °C. With p-nitrophenyl acetate as the substrate, the Km and kcat were determined to be 18.6 mM and 0.67 s-1, respectively, by steady-state kinetic assay. Molecular dynamics simulation and docking model structure revealed that p-nitrophenyl acetate could be the substrate of VvFrsA. In conclusion our results demonstrated that the protein was able to catalyze the hydrolysis of esters, especially p-nitrophenyl acetate, for the first time.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification*
  • Bacterial Proteins / metabolism*
  • Esterases / genetics
  • Esterases / isolation & purification*
  • Esterases / metabolism*
  • Esters / metabolism
  • Fermentation*
  • Hydrolysis
  • Models, Theoretical
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Respiration*
  • Substrate Specificity
  • Vibrio vulnificus / enzymology*

Substances

  • Bacterial Proteins
  • Esters
  • Recombinant Proteins
  • Esterases

Grants and funding

This work was supported by Natural Science Foundation of Jiangxi Province (20161ACB21012), Science and Technology Project Founded by the Education Department of Jiangxi Province (GJJ160353), and National Natural Science Foundation of China (31560250 and 31860249).