Brown R C, Fish W W, Hudson B G, Ebner K E
Biochim Biophys Acta. 1977 Mar 28;491(1):82-92. doi: 10.1016/0005-2795(77)90043-5.
alpha-Lactalbumin was purified to homogeneity from rat milk. Rat alpha-lactalbumin, in contrast to other alpha-lactalbumins, is a glycoprotein and exhibits an abnormally high molecular weight when obtained by gel filtration or electrophoresis in sodium dodecyl sulfate. The molecular weight by sedimentation equilibrium is 15 400 +/- 5% and of the reduced and alkylated protein is 16 000 when determined by thin-layer chromatography in 6 M guanidine hydrochloride. At least, three major charge forms, all containing carbohydrate and active in the lactose synthetase reaction were demonstrated. The amino acid composition reveals a high proline content which is reflected in a low alpha-helical content.
α-乳白蛋白从大鼠乳汁中纯化至同质。与其他α-乳白蛋白不同，大鼠α-乳白蛋白是一种糖蛋白，通过凝胶过滤或十二烷基硫酸钠电泳获得时，其分子量异常高。通过沉降平衡测定的分子量为15400±5%，在6M盐酸胍中通过薄层色谱法测定时，还原和烷基化蛋白的分子量为16000。至少证明了三种主要电荷形式，均含有碳水化合物且在乳糖合成酶反应中具有活性。氨基酸组成显示脯氨酸含量高，这反映在α-螺旋含量低上。
