Objective  Prokaryotic expression and acetylation modification of the LysR family transcription factor AphB protein were studied.

  Method  Primers of AphB of Vibrio alginolyticus HY9901 were designed based on the GenBank database No:WP_005380599.1. Heterologous induction was carried out by using E. coli expression system with optimized time, temperature, and IPTG concentration gradient. AphB protein was then purified to determine the degree of acetylation modification using anti-acetyl lysine specific antibody.

  Result  The full length of aphB gene was approximately 876 bp. After the bacterial solution was induced with 0.1 mmol·L⁻¹ of IPTG at 37 ℃ for 6 h, the expression of the fusion protein peaked. The purified fusion protein was 37.3 kD with an acetylation modification site. However, in vitro, the degree of acetylation was not regulated by deacetylase CobB.

  Conclusion  This study preliminarily determined AphB protein to be an acetylated protein that could not be enzymatically deacetylated by deacetylase CobB in vitro. The results reinforced the existing theory of acetylation modification in prokaryotic Vibrio and provided a valuable reference for studying the post-translation regulation mechanism of virulence gene aphB of V. alginolyticus.