东亚飞蝗谷胱甘肽S-转移酶分离纯化

通过硫酸铵沉淀技术和GSH-agarose亲和层析对东亚飞蝗Locusta migratoria manilensis(Meyen)5龄若虫谷胱甘肽S-转移酶(glutathione S-transferases,GSTs)进行了分离纯化。结果表明GSTs活性在硫酸铵各沉淀段均有分布,但在55%～100%沉淀段活性较高,在硫酸铵饱和度为85%时比活力最高,达到420.33μmol/min/mg protein,纯化倍数为18.86。根据硫酸铵粗沉淀谷胱甘肽S-转移酶结果,选择硫酸铵浓度为60%～90%沉淀段进行GSH-agarose亲和层析,纯化后比活力最高达到1365.29μmol/min/mg protein,纯化倍数达到61.25。经SDS-PAGE鉴定,得到的GST为1条带,亚基的分子量约为24kDa。

Purification of glutathione S-transferase from Locusta migratoria manilensis

Purification of glutathione S-transferase （GST） in the 5th nymphs of Locusta migratoria manilensis （Meyen） was conducted by ammonium sulfate fractionation and reduced glutathione affinity chromatography. The results showed that GST activity could be detected in every ammonium sulfate fractionation segment, but higher activity was detected under the saturation degree of 55 % - 100%, and the highest activity was found under 70% - 85 %. The specific activity determined with 1-chloro-2, 4-dinitrobenzene （CDNB） and GSH as the substrates was 420.33 μmol/min/mg protein, and the purification factor was 18.86-fold. A GST was purified 61.25-fold by using 60% - 90 % saturation ammonium sulfate precipitation followed by reduced glutathione affinity chromatography. The specific activity was 1 365.29 μmol/min/mg protein. SDS-PAGE showed that the molecular weight of the subunit was 24.4 kDa.