Abstract：The plasmid pET30a-SgACO, which contains 1-aminocyclopropane-1-carboxylate (ACC) oxidase （SgACO） gene from sugarcane (Sacharum sinensis Roxb), was transformed into Escherichia coli BL21 (DE3) plysS successfully, and the SgACO protein was expressed in BL21 (DE3). The SgACO was highly expressed in BL21 (DE3) in the presence of isopropyl-β-D-thiogalactopyranoside (IPTG) and most products existed in an inclusion body form. The final SgACO activity of 132.58 nmolC2H4/mg/h was obtained by one-step renaturation and purification of Ni2+- NTA column to the inclusion body protein. The renaturation and purification protein was relatively stable at the pH ranging from 5.5 to 8.0 and at the temperature ranging from 20 ℃ to 45 ℃. Its optimum pH was 6.7, optimum temperature was 33 ℃, Km was 61.77 μmol/L and Vm was 0.9647 μmol/min. The enzyme activity was activated by certain concentration of CO2 and ACC, and inhibited by Mg2+, Cu2+, Zn2+ and EDTA.
