【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α-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-Lg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。更多还原

【Abstract】 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 Tibetao 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.更多还原