Affinity chromatography for the purification of glutathione S-transferase from Oxya chinensis

Glutathione S-transferase (GST) in the fifth-instar nymphs of Oxya chinensis(Thunberg)was purified by ammonium sulfate and GSH-agrose affinity chromatography.Higher specific activity of GSTs could be detected at 60%-80% purity,and the highest specific activity was found at 90%.The specific activity was 0.3046 μmol/min/mg protein,and the purification factor was 1.82-fold.Further GSH-agrose affinity chromatography indicated that purification reached 50.88 with specific activity of 8.5185 μmol/min/mg protein.SDS-PAGE analysis indicated that the purified GSTs preparation had a single band with a relative molecular mass of 25.4 ku.These results provide the basis for further study of the enzymatic properties,structural characteristics and functions of the GSTs of O.chinensis.