苦瓜籽核糖体失活蛋白的分离纯化及抗氧化活性的研究

目的改进苦瓜籽核糖体失活蛋白的提取工艺 ,并对其抗氧化活性进行研究。方法苦瓜籽经粉碎 ,50mmol/L乙酸抽提 ,硫酸铵沉淀 ,经阳离子交换及凝胶柱色谱等步骤进一步纯化后 ,测定所得两种核糖体失活蛋白的理化性质。结果纯化后得到一种分子量为 2 9.6kD的蛋白质和一种小分子量蛋白质 ,两者在无细胞系统中抑制50 %蛋白质合成浓度分别为 4 .3× 1 0 - 6 、1 .4× 1 0 - 6 mol/L ,含糖量分别为 4 .83 %、1 .82 % ,类超氧化物歧化酶 (SOD)活性分别为 79.0 5、1 7.2 5u/mg。阳性对照纯品SOD活性为 1 2 67u/mg。结论从苦瓜籽中分离纯化出两种不同分子量的核糖体失活蛋白均为糖蛋白质 ,且具有一定的抗氧化活性

Isolation, purification and anti-oxidation of ribosome-inactivated proteins from seeds of Momordica charantia L.

PurposeTo improve the isolating technology of ribosome inactivating protein of Momordica charantia and to study their anti oxidatiion activity. MethodsThe seeds of Momordica charantia were smashed and isolated with 50 mmol/L acetic acid, precipitated with (NH 4) 2SO 4 and purified by CM32,Sephadex G 75 column chromatography. The physical and chemical characters of two ribosome inactivating proteins were identified.ResultsAfter purifying, one kind of protein whose molecular weight was 29.6 kD and other,below 10.0 kD were obtained. 29.6 kD protein had inhibitory action upon protein synthesis in reticulocyte lysate and its IC 50 was 4.3×10 -6 mol/L, and the small molecular weight protein was 1.4×10 -6 mol/L. The sugar content of 29.6 kD protein was 4.83% and the small protein was 1.82%. The semi SOD activity of 29.6 kD was 79.05 u/mg protein, and the semi SOD activity of the small protein was 17.25 u/mg protein. The positive contrast of the activity of pure SOD was 1 267 u/mg protein. ConclusionTwo kinds of proteins had different molecular weights were isdated and purified. These two kinds of protein were glycoprotein, and had some anti oxidation activity.