大阪鲫鱼两种卵黄蛋白紫外吸收特性的研究

CHARACTERISTICS OF ULTRAVIOLET ABSORPTIVE SPECTRUM OF LIPOVITELLIN AND YOLK PROTEIN L IN CRASSIUS AURATUS CUVIERI

采用大柱制备电泳的方法从大阪鲫鱼卵巢中提纯出两种蛋白质:卵黄脂磷蛋白和类似于卵黄高磷蛋白的卵黄蛋白L.分析了两种蛋白的氨基酸组成,并对两种蛋白的紫外吸收和紫外吸收四阶导数谱特性进行了分析研究。发现卵黄脂磷蛋白在溶液的pH改变(pH3.12-8.12-11.00)时,紫外吸收谱和四阶导数谱未发生明显变化,而卵黄蛋白L在溶液的pH改变(pH7.66-9.35-11.89)时,其紫外吸收谱最大吸收波长红移,紫外吸收四阶导数谱出现新的未知峰,发生显著变化。这表明卵黄脂磷蛋白所含的大量脂类存在于蛋白质分子的表面,从而影响了蛋白质分子中产生紫外吸收的氨基酸—酪氨酸、色氨酸、苯丙氨酸的紫外吸收。在卵黄蛋白L中,这几种氨基酸则位于蛋白质分子的表面,从而对溶液pH的变化尤为敏感。

A preparative PAGE was used to pruify two proteins: lipovitellin and yolk protein L (a protein similar to phosvitin). The amino acid composition was detected. The ultraviolet absorptive spectrum and four dimensions derivative ultraviolet absorptive spectrum were studied. When the pH of the solution of lipovitellin changed from 3.12 to 8.12 and then 11.00, the absorptive spectrum of ultraviolet and four dimensions derivation ultraviolet had no obvious change. But when the pH of the solution of yolk protein L changed from 7.66 to 9.35 and then 11.89, the maximum absorptive wave length of ultraviolet absorptive spectrum red shifted. Unknown peaks and the peaks caused by Tyrosine, Phenylalanin and Tryptophane emerged in four dimensions derivative ultraviolet absorptive spectrum and the wave length of absorptive peaks changed with the pH of the solution. This suggested that in yolk protein L, this amino acids causing ultraviolet absortion exist at the surface of protein molecules and their characteristics of absorption change with the pH of the solution because of the alteration of molecule conformation. Lipovitell in molecules had plenty of lipoid and it hindered the change of molecular conformation.