The Comparison For Properties Of Superoxide Dismutase In Different Species Of Shrimps

The article took Penaeus japonicus for example to detect the extract conditions ofsuperoxide dismutase(SOD) in shrimps, and analyzed the properties of SOD in Penaeusjaponicus, Procambarus clarkii, Litopenaeus vannamei, then made the comparison ofisoenzymes in the three species of shrimps. SOD is the important index of oxygenic metabolismand immunity for organisms. So the research about SOD of different species of shrimps affordsthe basic information for the biological theories and immune mechanisms and offers the basis forhealthy breed, disease prevention and cure and new pharmic exploitation of shrimps.The experiments were done to find out the appropriate conditions of SOD purified from themuscle tissue of Penaeus japonicus. When the pH of extract buffer was at 6.5, the highestactivity of SOD was achieved. The heat treatment of 65℃ and 70-90% saturated ammoniumsulfate could fractionated the protein. The active fraction yielded by DEAE-32 columnchromatography under eluting buffer, pH7.8 was collected, SOD at higher purity was primarilyobtained. PAGE identified that the protein bands had activity of SOD. Cu,Zn-SOD was madecertain by the sensitivity of chloroform/ethanol.It was found that the calcium ion restrained the SOD activity of the muscle tissue fromPenaeus japonicus, but it was not intense in the scale determined. The ions of copper, zinc,manganese promoted the activity in the lower concentration, but inhibited it in the higherconcentration evidently. Four ions affected the SOD activity of the muscle tissue fromProcambarus clarkii and Litopenaeus vannamei as in Penaeus japonicus by copper, thedifference lying in the degree of the effect. SDS and EDTA controlled the SOD activity fromPenaeus japonicus and Procambarus clarkii distinctly. SDS restrained the activity fromLitopenaeus vannamei evidently, but EDTA promoted it. It is possible reason that thestructures of the protein from different shrimps are not in the same.The difference of the SOD activity was not evident in the muscle, gill tissues from thethree species of shrimps. The activity in the hepatopancreas was higher than that in the othertissues. There was no distinct difference in the three shrimps for the activity of the muscle,gill tissues, while it lay in evidently for the hepatopancreas.After the gel exclusion chromatography, there were two bands in the muscle and thehepatopancreas, one band in the gill of Penaeus japonicus, but the speed of chromatographywas different among those bands;two bands in the three tissues of Procambarus clarkii withthe same speed;one band in the muscle and the gill, two bands in the hepatopancreas ofLitopenaeus vannamei with different speed of chromatography. Cu,Zn-SOD was made certainby the sensitivity of chloroform/ethanol and H2O2. The difference of the gene expression islikely to be the reason of the isozymes' differences.