Aster J C, Brewer G J, Hanash S M, Maisel H
Biochem J. 1984 Dec 1;224(2):609-16. doi: 10.1042/bj2240609.
Bovine lens epithelium, cortex and nucleus were screened for the presence of red-cell-membrane band 4.1-like proteins by using an immunoblot method. Lens epithelial cells were found to contain proteins of Mr 78 000 and higher (approximately 150 000) that cross-reacted with anti-(protein 4.1) sera. Fibre cells of the superficial cortex were also found to contain these two proteins, as well as an additional protein of approx. 80 000 Mr. In contrast, deep layers of the cortex and the lens nucleus contained no detectable cross-reactive protein at these Mr values. Treatment of a crude membrane fraction prepared from superficial bovine cortices with a low-ionic-strength buffer resulted in release of the high-Mr band 4.1-like protein. The 80 000- and 78 000-Mr proteins remained with the membrane fraction in low-ionic-strength buffer, but were released into solution by high-ionic-strength-buffer treatment. We have also demonstrated that the human red-blood-cell membrane, like lens epithelial cells and fibre cells, also contains a high-Mr band 4.1-like protein that is released from membranes by low-ionic-strength-buffer treatment.
采用免疫印迹法对牛晶状体上皮、皮质和核进行筛选，以检测是否存在红细胞膜带4.1样蛋白。发现晶状体上皮细胞含有分子量为78000及以上（约150000）的蛋白，这些蛋白与抗（蛋白4.1）血清发生交叉反应。还发现表层皮质的纤维细胞含有这两种蛋白，以及另一种分子量约为80000的蛋白。相比之下，皮质深层和晶状体核在这些分子量值下未检测到交叉反应蛋白。用低离子强度缓冲液处理从牛表层皮质制备的粗膜组分，可使高分子量的带4.1样蛋白释放出来。分子量为80000和78000的蛋白在低离子强度缓冲液中仍留在膜组分中，但通过高离子强度缓冲液处理可释放到溶液中。我们还证明，人红细胞膜与晶状体上皮细胞和纤维细胞一样，也含有一种高分子量的带4.1样蛋白，该蛋白可通过低离子强度缓冲液处理从膜中释放出来。
