摘要
对猪血浆α２巨球蛋白性质研究表明其大部分理化性质与人α２巨球蛋白十分相似。而且猪α２巨球蛋白也存在有活性的天然的Ｓｌｏｗ－Ｆｏｒｍ和构象发生变化并不可逆失活的Ｆａｓｔ－Ｆｏｒｍ。猪α２巨球蛋白经测定其ｐＩ为４．５５，５．１。紫外吸收光谱在２７６ｍｍ处有最大吸收，Ｅ＝９．１４。其糖含量为９．３％。氨其酸组成分析表明酸性氨基酸含量较高。圆二色谱分析说明分子中含有较多的β折叠。它还具有连接锌离子的性质。
?-Macroglobulin is one of the major proteinase inhibitors of blood plasma. In this paper,some properties of porcine plasma α2M were studied. The isoelectric points of porcine α2M are 4. 5, 5. 1 given by isoelectric focusing electrophoresis.The highest absorption of ultraviolet absorption spectrum of porcine α2M is at 276nm. Its absorption coefficient at 280nm is 9.14. The carbohydrate content of porcine α2M is about 9.3 precent determined by phenol-sulfurie acid method. The CD spectrum revealed a high βstructure content in the molecule. Analysis of amino acid composition of porcine α2M showed that there was a high acidic amino acid content which was similar to that of human α2M. Equillibrium dialysis experiments indicated that 16mol Zine could bind to 1mol native porcine α2M in the 10mol/L ZnCl2 solution in vitro. Treatment of porcine α2M with trypsin and ammonium salts produced a form of the molecule more mobile in electrophoresis. This experiment indicated that porcine α2M had the porperty of electrophoretically 'Slow' and 'Fast' forms which were the same as that of human α2M.
出处
《生物化学杂志》
CAS
CSCD
1994年第5期527-532,共6页
关键词
猪
血浆
Α2巨球蛋白
Plasma of pig
α_2-Macroglobulin
