牦牛肝蛋白分离纯化及其抗氧化活性研究(英文)

新鲜牦牛肝匀浆、磷酸缓冲液抽提、硫酸铵分级沉淀,并采用响应面法对提取条件进行优化。在最佳提取条件下提取的粗蛋白经DEAE-52离子交换层析和Sephadex G-200凝胶柱洗脱得到7种不同的蛋白。用SDS-聚丙烯酰胺凝胶电泳对各蛋白的分析结果,各蛋白均成单一条带表明纯化效果较好,其分子量分布在97.2 KD-116 KD之间。采用化学发光法对其在体外抗氧化活性研究,主要包括超氧阴离子自由基、羟自由基、1,1-二苯基-2-三硝基苯肼自由基的清除实验,结果表明几种蛋白均具有抗氧化作用,尤其蛋白5和蛋白1作用较为突出,在250 mg/L浓度时,对超氧阴离子的清除率为82.91%和72.92%。上述结果为牦牛肝作为抗氧化保健食品或功能食品的研究和开发提供了依据。

Isolation and Purification of Proteins in Liver of Yak (Bos grunniens) and Its Antioxidant Activities

Seven proteins(BGP1,BGP2,BGP3,BGP4,BGP5,GBP6,and BGP7) were isolated respectively from the liver of yak(Bos grunniens) by homogenizing,step precipitating with ammonium sulfate,ion-exchange chromatography on DEAE-52 and gel filtration chromatography on Sephadex G-200.Each protein gave a single band on SDS-PAGE and the molecular weight of those proteins were from 97.2 KD to 116 KD.The anti-oxidant activities of proteins were evaluated using the method of chemistry luminescence,including 1,1-diphenyl-2-picrylhydrazyl(DPPH·),superoxide(O-·2) and hydroxyl(·OH) radical scavenging assays.The proteins could scavenge superoxide radical,hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl(DPPH·).Especially,the effects of BGP5 and BGP1 on scavenging superoxide free radical were obvious,with scavenging ability 82.91% and 72.92% at the concentrations of 250 mg/L.The results indicated that proteins may be exploited as health food or functional food.