Chianese L, Garro G, Mauriello R, Laezza P, Ferranti P, Addeo F
Dipartimento di Scienza degli Alimenti, Università degli Studi di Napoli, Portici, Italia.
J Dairy Res. 1996 Feb;63(1):49-59. doi: 10.1017/s0022029900031538.
Five ovine alpha s1-casein variants (A-E) were identified in an Italian population sample using gel electrophoresis at alkaline pH, gel isoelectric focusing, two dimensional gel electrophoresis, and immunoblotting with polyclonal antibodies against alpha s1-casein. Each casein sample produced two peaks by fast reversed-phase HPLC. Gel isoelectric focusing and electrospray mass spectrometry were used to demonstrate that the first HPLC peak contained the 191 residue alpha s1-casein molecular species and the second the 199 residue species, in proportions of approximately 20:80. Only in the case of the sample containing alpha s1-casein CE was the method for the separation of the single short and long forms of each variant unsuccessful. Both two dimensional electrophoresis followed by staining with polyclonal antibodies against alpha s1-casein and electrospray mass spectrometry showed a heterogeneity consistent with that expected from a protein chain with three levels of phosphorylation and two different lengths. However, especially for alpha s1-caseins D and E, a further uncharacterized heterogeneity was detected.
在一个意大利人群样本中，通过碱性pH条件下的凝胶电泳、凝胶等电聚焦、二维凝胶电泳以及使用抗αs1-酪蛋白的多克隆抗体进行免疫印迹，鉴定出了五种绵羊αs1-酪蛋白变体（A-E）。每个酪蛋白样品通过快速反相高效液相色谱产生两个峰。凝胶等电聚焦和电喷雾质谱用于证明第一个高效液相色谱峰包含191个残基的αs1-酪蛋白分子种类，第二个峰包含199个残基的种类，比例约为20:80。仅在含有αs1-酪蛋白CE的样品中，分离每个变体的单一短链和长链形式的方法未成功。二维电泳后用抗αs1-酪蛋白的多克隆抗体染色以及电喷雾质谱均显示出与具有三级磷酸化和两种不同长度的蛋白质链预期相符的异质性。然而，特别是对于αs1-酪蛋白D和E，检测到了进一步的未表征异质性。
