草地藏系绵羊乳游离氨基酸质量分数及蛋白遗传多态性研究  

A Study of Dissociative Amino Acid Contents and Protein Genetic Polymorphisms in Milk of Tibetan Sheep

作　　者：王永[1] 郑玉才[2] 梁梓[2] 马嵬[2] 胡瑜[3] 刘鲁蜀[2] 金素钰[2] 傅昌秀[4] 陶永平[3] 

机构地区：[1]甘肃农业大学动物科学技术学院,甘肃兰州730070 [2]西南民族大学生命科学与技术学院,四川成都610041 [3]四川省若尔盖县畜牧局,四川若尔盖624500 [4]四川省畜禽繁育改良总站,四川成都610041

出　　处：《氨基酸和生物资源》2006年第2期1-6,11,共7页Amino Acids & Biotic Resources

基　　金：四川省十五攻关项目(02NG004-056);国家民委重点项目(03N010)的部分内容

摘　　要：用反相高效液相色谱法检测草地藏系绵羊乳游离氨基酸质量分数，用聚丙烯酰胺凝胶电泳法研究乳蛋白组分及其遗传多态性。结果表明：草地藏系绵羊乳中检测到17种游离氨基酸，其中质量分数最高的为Arg；与金堂黑山羊乳比较17种游离氨基酸中，甲硫氨酸的质量分数极显著高于金堂黑山羊（P〈0．01），而天冬氨酸、甘氨酸、赖氨酸、谷氨酸、苏氨酸、丙氨酸和缬氨酸的质量分数均显著低于金堂黑山羊（P〈0．05），其余9种游离氨基酸质量分数未发现明显差异，但两种羊乳中的必需氨基酸总量基本相同，差异不明显（P〉0．05）。草地藏系绵羊乳蛋白组分主要包括d-La、β-Lg、CN、IgG等，CN的相对质量分数约50％～52％；研究还发现4种分子量类型的乳上皮粘蛋白MUC1，分子量分别为214kD、209kD、207kD、205kD；CN、β-k均未检测到多态性．说明草地藏系绵羊乳蛋白遗传多态性较为贫乏。The dissociative amino acid contents , protein compositions and genetic polymorphisms in milk were studied by reversed phase high press liquor chromatography （ RP - HPLC ） and polyacrylamide gel electrophoresis （PAGE） respectively. The results showed that 17 kinds of dissociative amino acids were identified in Tibetan sheep milk, and the arginine was the most abundant one in all milk samples . The methinine content inTibetan sheep milk was remarkably more than that in Jintang black goat milk （ p 〈 0.01 ）, while the contents of aspartic acid, glycine, lysine, glutamate, threonine, alanine and valine in Tibetan sheep milk were lower significantly than that in Jintang black goat milk （ p 〈 0.05 ）. The differences of contents of other 9 kinds of dissociative amino acids and the total amount of essential amino acids in milk were insignificantly （ p 〉 0.05 ） between Tibetan sheep and Jintang black goat. Main protein components in Tibetan sheep skim milk comprised α -lactalbumin, β-lactoglobulin, IgG, casein, the relative percentage of casein was 50% -52% approximately. 4 kinds of molecular weight type of milk mucin 1 （ MUC1 ） were discovered in this study, with molecular weights of 214 kD, 209 kD, 207 kD and 205 kD, respectively. No polymorphisms were observed in casein and β - lactoglobulin. The results suggests that the Tibetan sheep milk proteins be poor in genetic polymorphism.

关 键 词：草地藏系绵羊 乳 游离氨基酸 蛋白遗传多态性 

分 类 号：S827[农业科学—畜牧学]