Bacillus sp. SCSIO 15029中一种耐高温Mn-超氧化物歧化酶的克隆、表达及鉴定

摘要

A putative superoxide dismutase gene (BaSOD) was cloned from Bacillus sp. SCSIO 15029, which was isolated from the sediment of the South China Sea. The BaSOD gene was expressed in Escherichia coli BL21(DE3) by using pET-28a(+) expression system. The recombinant enzyme was soluble in E. coli, and its biochemical properties were studied. BaSOD exhibits maximum activity at pH 7.5 and 40℃ with a specific activity of BaSOD at 5511.46 U·mg–1. BaSOD is a manganese-dependent superoxide dismutase. The enzyme activity was basically not affected after incubation at 60℃ for 30 min. The residual activity was 71% after incubation at 70℃ for 30 min. BaSOD shows good thermo-stability and possesses very good potential for industrial utilization.%本研究从南海沉积物中分离到一株耐高温菌 Bacillus sp. SCSIO 15029,从其基因组中克隆了一个编码超氧化物歧化酶的基因BaSOD,并在大肠杆菌BL21(DE3)中实现了可溶性异源表达。随后,对重组BaSOD进行了酶学性质鉴定, BaSOD的最适pH为7.5,最适反应温度为40℃,酶活为5511.46U·mg–1。经鉴定, BaSOD是一种锰离子特异的超氧化物歧化酶(superoxide dismutase, SOD),该酶具有良好的热稳定性,在60℃处理30min酶活基本没有变化,在70℃下处理30min剩余酶活为71%,具有较好的工业应用前景。