Cattaneo T M, Nigro F, Toppino P M, Denti V
Istituto Sperimentale Lattiero-Caseario, Lodi (MI), Italy.
J Chromatogr A. 1996 Jan 19;721(2):345-9. doi: 10.1016/0021-9673(95)00780-6.
The purpose of the present work was to develop a procedure able to separate and identify the major protein components of ewe's milk by capillary zone electrophoresis (CZE). Thirty-five individual milk samples of Massese breed were analyzed using a coated capillary. The analyses were performed at pH 3.0 at a temperature of 40 degrees C in the presence of 6 M urea. The purification of casein fractions was carried out by preparative fast protein liquid chromatography and the CZE results were confirmed by polyacrylamide agarose gel electrophoresis (PAAGE). The identification of whey proteins was also carried out by comparison with high-performance liquid chromatography data. The present study permitted the identification of the major components of ewe's milk by high-resolution electropherograms and characteristic migration times (tM). it was also possible to detect the presence of genetic variants of beta-lactoglobulin. The tM of k-casein was determined after enzymatic action of chymosin by verifying the simultaneous formation of p-k-casein. In most of the samples a fast moving alpha-s2-casein variant was identified by comparison with PAAGE results. Minor genetic differences were found in other casein fractions for this pool of samples.
本研究的目的是开发一种能够通过毛细管区带电泳（CZE）分离和鉴定母羊乳主要蛋白质成分的方法。使用涂覆毛细管对35份马塞塞品种的个体乳样进行了分析。分析在pH 3.0、40℃温度下于6 M尿素存在的条件下进行。通过制备型快速蛋白质液相色谱法对酪蛋白组分进行纯化，并通过聚丙烯酰胺琼脂糖凝胶电泳（PAAGE）确认CZE结果。还通过与高效液相色谱数据比较对乳清蛋白进行了鉴定。本研究通过高分辨率电泳图谱和特征迁移时间（tM）实现了对母羊乳主要成分的鉴定。还能够检测到β-乳球蛋白的遗传变体的存在。通过验证同时形成的对-κ-酪蛋白，在凝乳酶的酶促作用后测定了κ-酪蛋白的tM。通过与PAAGE结果比较，在大多数样品中鉴定出一种快速迁移的α-s2-酪蛋白变体。对于这组样品，在其他酪蛋白组分中发现了微小的遗传差异。
