A study of polymorphism in milk proteins from local and imported dairy sheep in Australia by capillary electrophoresis
- 作者：Patrick Clé ; ment ; Samson O. Agboola and Roberta Bencini
- 关键词：Milk ; Proteins ; Caseins ; Sheep ; Capillary electrophoresis
- 刊名：Lebensmittel-Wissenschaft und -Technologie
- 出版年：2006
- 期刊代码：121_00236438
- 类别：abs
- 出版时间：2006
- 卷：39
- 期：1
- 页码：63-69
- 文件大小：266 K
摘要
Casein and whey protein fractions of milk obtained from 47 ewes of five breeds or crossbreeds (Awassi, Merino, East Friesian×Merino, Awassi×Merino and Awassi×East Friesian) were analysed by capillary electrophoresis (CE). The experiments were performed on a Beckman P/ACE™ system 5510 with an uncoated fused-silica capillary and a low pH buffer containing urea and a polymeric additive. The four major caseins (αs1-, αs2-, β- and κ-casein) in an acid precipitate were well separated, as were the two whey proteins, decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6WMV-4GFVMPG-1&_mathId=mml1&_user=10&_cdi=6944&_rdoc=9&_handle=V-WA-A-W-AC-MsSAYZW-UUA-U-AABZWZYCEZ-AABBYVEBEZ-CADBZYWBE-AC-U&_acct=C000050221&_version=1&_userid=10&md5=b848a6a2f857c7b838b2d628c4a22abb" title="Click to view the MathML source">α-lactalbumin (α-La) and β-lactoglobulin (β-Lg). The electromigration of the proteins was in the order of α-La, β-Lg, αs2-CN, αs1-CN, κ-CN and β-CN. The milk samples were composed of the same variant of decoration:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6WMV-4GFVMPG-1&_mathId=mml2&_user=10&_cdi=6944&_rdoc=9&_handle=V-WA-A-W-AC-MsSAYZW-UUA-U-AABZWZYCEZ-AABBYVEBEZ-CADBZYWBE-AC-U&_acct=C000050221&_version=1&_userid=10&md5=931232b778eda567368304d380eb7910" title="Click to view the MathML source">α-La and two different genotypes (A and B) of β-Lg while the β-Lg AB genotype was evident in the milk of some animals. The αs1-CN fractions displayed considerable heterogeneity with at least 4 different peaks, representing 4 different variants. A fifth peak, corresponding to the Welsh variant (or αs1-CN D), was present in 90%of the ewes’ milk samples. The κ-CN fraction was resolved as a single peak, while the β-CN revealed significant heterogeneity with 3 variants. It appears that the presence of the αs1-CN Welsh variant in Merino ewe and its crosses with Awassi and East Friesian ewes adversely affected milk composition and yield.