Prasad R, Hudson B G, Strickland D K, Ebner K E
J Biol Chem. 1980 Feb 25;255(4):1248-51.
Rat alpha-lactalbumin is unique in contrast to alpha-lactalbumin isolated from other species in that it exists in three charge forms. Each form contains carbohydrate and is active in the lactose synthetase reaction. Form II comprises about 80% of the total alpha-lactalbumin and contains a single heteropolysaccharide unit which is attached to the polypeptide chain at Asn45. The detailed structure of this unit was ascertained using specific exoglycosidases, endoglycosidases, and methylation analysis. The following structure is proposed for the heteropolysaccharide unit: (formula: see text).
与从其他物种分离得到的α-乳白蛋白相比，大鼠α-乳白蛋白的独特之处在于它以三种电荷形式存在。每种形式都含有碳水化合物，并且在乳糖合成酶反应中具有活性。形式II约占总α-乳白蛋白的80%，含有一个单一的杂多糖单元，该单元在Asn45处连接到多肽链上。使用特定的外切糖苷酶、内切糖苷酶和甲基化分析确定了该单元的详细结构。提出了以下杂多糖单元的结构：（化学式：见正文）。
