Research On Purification Of Copper/Zinc Superoxide Dismutase From Porcine Blood

Superoxide dismutase is a kind of metal enzyme that could catalyze the reaction of superoxide anion free radical, and create oxygen and catalyses. Every kind of living creature has superoxide dismutase. At present,superoxide dismutase has been acquired from germs, algae, fungi, plant, insect, fish, birds and animal, and it has been extensively applied to the daily life, such as the cosmetics, medicine, food and the examination of some diseases. Because of the low immunogenic, high content and activity of SOD in animal, it is isolated and purified from animal's blood. With the development of the livestock breeding,the resource of procine blood is becoming more and more. However, most of the procine blood can't be used, which waste the resource and pollute the surrounding. SOD is produced from swine blood, which is a good thing that can make good profits. According to these reasons, Superoxide dismutase(SOD), which plays a very inportant role in protecting organisms from oxygen toxicity, was purified from porcine erythrocyte in this paper. The stability of SOD was also studied in this paper. 1 , Separation and purificationFirst, erythrocyte membrances were disintegrated via freeze-thraw methods in the presence of Triton X-100. Second, porcine eythrocyte coarse CuZn-SOD wasobtained by several steps, which were about removing hemoglobin by ethanol and chloroform firstly, extraction by dipotassium hydrogen phosphate secondly, precipitation by acetone thirdly, heat denaturation fourthly, etc. In the end, through DEAE Sephadex A-50, it was completely purified. Hie yield and the specific activity of SOD after this process were 57% and 5863U/mg, respectively. Purified SOD was testified by PAGE electrophoresis. 2, Stability studyTemperature and pH value are two important factors that affect the activity of. SOD and SOD has a good stability on the condition of them. The enzymatic activity is comparatively stable below 60 "C, for example, the crude SOD solution being kept in 60°C for 30 minute, the enzymatic activity only reduces 24%;however the temperature raised higher than 70 °C, the activity reduces obviously, such as reducing 59% on the condition of 70"C for 30 minute and 74% on the condition of 80V for 30 minutes. The enzymatic activity is stable within pH 5~9;Onee exceeding this range, it reduces deeply. For example, the rest activity is 60% on the condition of pH 4.0 and 58% on the condition of pH 10.0. The activity is nothing on the condition of pH 12.