创伤弧菌膦酸乙醛水解酶PhnX的重组表达、活性分析及晶体生长OA北大核心

Phosphorus(P)is an essential nutrient for life.P limitation often occurs in the oceans;marine microor-ganisms can utilize inorganic phosphate(Pi)and organophosphorus compounds such as phosphonates as a P-acquisition strategy.2-Aminoethylphosphonate is the most common phosphonate,and phosphonoacetaldehyde hydrolase(PhnX)is a key enzyme in converting phosphonate to Pi.However,the enzymatic properties of PhnX in marine bacteria have been rarely studied.In this effort,we successfully expressed and purified PhnX from Vibrio vulnificus(Vv PhnX),which demonstrated significant enzymatic activity.Gel filtration experiments indicated Vv PhnX to exist as a stable and soluble homomeric enzyme with a monomer molecular mass of～29.5 kDa.Thermal shift experiments indicated the melting temperature to be～37℃.After incubation at 20-70℃for 1 h,the residual activity of Vv PhnX declined with rising temperature.After incubation at 30℃for 1 h,the enzyme activity declined by～30%.At 40℃,the activity dropped by～80%and was nearly lost after 1 h at≥50℃;these results indicated the enzyme to have moderate thermal stability.The well-shaped crystals of the Vv PhnX protein were obtained,and they were suitable for X-ray analysis.Overall,this research provides valuable insights into the biological function of PhnX and its role in the marine P cycle.