猕猴桃蛋白质的分离及类型鉴定

SEPARATION AND TYPE IDENTIFICATION OF PROTEIN IN KIWI FRUIT

用乙醇做提取剂从猕猴桃汁中提取总蛋白,对总蛋白中的蛋白质含量进行了测定,通过硫酸铵等电点沉淀、透析及Sepharose CL—6B柱层析分离出两种蛋白质,220 nm紫外检测结合苯酚硫酸法跟踪检测,初步推断两种蛋白质为相对分子质量不同的糖蛋白,分别收集洗脱峰进行冷冻干燥,得到干粉,测定蛋白质与糖的比值分别为1.156和1.209,红外光谱分析更进一步验证了两种均为糖蛋白,β-消去反应证明都含有O-糖苷键.

The total protein was extracted from the juice of kiwi fruit by using ethanol as extracting solvent, the protein content in the total protein was determined, and two kinds of protein were separated by ammonium sulfate isoelectric precipitation, dialysis and column chromatography with Sepharose CL-6B. It is concluded initially by 220 nm ultraviolet detection in combination with phenol-sulfuric acid tracking detection method that the two kinds of protein are glycoproteins with different relative molecular weights. The glycoproteins were collected respectively and then lyophilized to obtain dry powder, and the ratios of protein to saccharide in the two kinds of glycoprotein were respectively 1. 156 and 1. 209. The IR spectral analysis further verifies that both of the proteins are glycoprotein, and β-elimination reaction proves that both of them contain O-glycosidic bond.