猪脂肪沉积相关的生化特征研究

THE STUDY OF THE BIOCHEMICAL CHARACTERISTICS RELATED TO FAT DEPOSITION OF PIGS

以遗传瘦肉型的斯格猪和长白猪以及遗传脂肪型的通城猪和太湖猪为动物样本 ,分析了血清中激素敏感脂酶 ,肌肉组织中氨基酸组成、含量和克分子比 ,分离纯化了肌细胞和脂肪细胞质和膜 ,并对其膜蛋白进行了SDS PAGE比较分析。结果表明 ,脂肪型的通城猪血中激素敏感脂酶活性比瘦肉型的长白猪高近 3倍 ,2猪种中雌雄差异不显著。脂肪型的通城猪与太湖猪肌细胞蛋白质中的氨基酸组成及含量十分相似 ,瘦肉型的斯格和长白猪的氨基酸含量却显著地高于脂肪型的通城和太湖猪。氨基酸组分中 ,瘦肉型猪的 3种碱性氨基酸 (Lys、Arg和His)、2种典型的疏水氨基酸 (Leu和Ile)、易形成疏水核的苯丙氨酸以及形成二硫键的半胱氨酸均显著的高于脂肪型 ,这与瘦肉型猪蛋白质的溶解性能较差相关。蛋白质的SDS PAGE分析发现 ,脂肪型猪肌细胞质中存在一种分子量约 4 4 7kDa ,与脂肪沉积相关的蛋白质。脂肪细胞膜中的 94kDa蛋白也显示与脂肪沉积的遗传特征相关 ,另外 ,脂肪型的通城猪性成熟前后肌细胞膜上存在蛋白质组分差异。

Using Sige pigs and Landrace pigs of the genetically lean and Tongcheng pigs and Taihu pigs of the genetically obese as animal samples,hormone sensitive lipase in sera,amino acid composition and mole ratio of amino acids of myocyte were analysed.The myocyte and the adipocyte membrane were seperated and purified.In addition the proteins in the myocyte plasma and membrane and the adipocyte membrane proteins were all comparatively analysed with SDS-PAGE method.The results showed that the activity of hormone sensitive lipase in sera of the obese Tongcheng pigs was about three times higher than that of the lean Landrace pigs,and the differences between male and female were not notable in the above mentioned two kinds of pigs.The amino acid composition and content of proteins in both myocytes of the obese Tongcheng pigs and Taihu pigs were surprisingly similar but the amino acid composition of proteins in Sige and Landrace pigs myocytes of the genetically lean was notably higher than that of obese Tongcheng and Taihu pigs.As to the amino acid composition,the content of three base amino acids (Lys,Arg and His),two typical hydrophobic amino acids (Leu and Ile),Phe and Cys of the proteins in the myocyte of the lean pigs were notably higher than that in the obese pigs,which was closely related to the poor solubility of the proteins of the lean pigs.The SDS PAGE analysis of proteins found that there existed one kind of approximately MW 44 7kDa proteins in the myocytes of the obese pigs which was related to fat deposition.The 94kDa proteins in adipocyte membrane were also showed to be related to the genetical characteristics of fat deposition.Further analysis showed that the 44 7kDa protein were nonglycosylated protein while the 94kDa protein were typically glycosylated protein.