Wu-Chou S, Robinson A E, Hrabeta E, Packer L
Biochem Biophys Res Commun. 1984 Oct 30;124(2):565-71. doi: 10.1016/0006-291x(84)91591-2.
Specific carboxyl modification of purple membrane using a water-soluble carbodiimide yielded a mixture of oligomers, revealed by gel electrophoresis. Purple membrane pre-treated with papain or trypsin, cleaving the C-terminal tail, showed the same pattern of cross-linked products. Chymotryptic cleavage released amino acids 1-72 (7kD fragment) from the cross-linked products, as it did with native membrane. The tail and helices A and B are not, therefore, involved in carbodiimide-promoted cross-linking. Similar cleavage of a hydrophobic dihydroquinoline-modified sample showed that mainly intra-molecular cross-linking occurs, with little cross-linking between the large and small chymotryptic fragments.
使用水溶性碳二亚胺对紫膜进行特定的羧基修饰，通过凝胶电泳显示得到了寡聚体混合物。用木瓜蛋白酶或胰蛋白酶预处理紫膜，切割C末端尾巴，显示出相同的交联产物模式。胰凝乳蛋白酶切割从交联产物中释放出氨基酸1 - 72（7kD片段），就像对天然膜所做的那样。因此，尾巴以及螺旋A和B不参与碳二亚胺促进的交联。对疏水性二氢喹啉修饰样品的类似切割表明，主要发生分子内交联，大小胰凝乳蛋白酶片段之间几乎没有交联。
