Nakano T, Ikai A, Nishigai M, Noda H
J Biochem. 1979 May;85(5):1339-46.
Rhodopsin from the bovine rod outer segment contains a covalently linked carbohydrate moiety (Heller, J. & Lawrence, M.A. (1973) Biochemistry 9, 864--868). We studied the location of this carbohydrate moiety on the disk membrane by using ferritin-conjugated concanavalin A and concanavalin A labelled with fluorescein isothiocyanate. Electron microscopic observation of sonicated disk membrane that was labelled with ferritin-concanavalin A revealed the electron-dense image of ferritin on the inner surface of the disk membrane and not on its outer surface. Intact disk membrane that was similarly treated with ferritin-concanavalin A showed a complete absence of ferritin molecules on its surface. In an independent series of experiments we confirmed that the sonicated disk membrane bound three to five times more fluorescein-labelled concanavalin A than the intact disk membrane did. From these experiments we conclude that the carbohydrate moiety of bovine rhodopsin is located on the inner surface of the disk membrane, in agreement with the report by Rohlich on the frog rod outer segment disk membrane (Rohlich, P. (1976) Nature 263, 789--791).
来自牛视杆细胞外段的视紫红质含有一个共价连接的碳水化合物部分（赫勒，J. 和劳伦斯，M.A.（1973年）《生物化学》9，864 - 868）。我们通过使用铁蛋白偶联的伴刀豆球蛋白A和异硫氰酸荧光素标记的伴刀豆球蛋白A来研究这个碳水化合物部分在盘膜上的位置。用铁蛋白偶联的伴刀豆球蛋白A标记的超声处理后的盘膜的电子显微镜观察显示，铁蛋白的电子致密图像出现在盘膜的内表面而非外表面。用铁蛋白偶联的伴刀豆球蛋白A进行类似处理的完整盘膜在其表面完全没有铁蛋白分子。在一系列独立实验中，我们证实超声处理后的盘膜结合的荧光素标记的伴刀豆球蛋白A比完整盘膜多三到五倍。从这些实验中我们得出结论，牛视紫红质的碳水化合物部分位于盘膜的内表面，这与罗利克关于蛙视杆细胞外段盘膜的报告一致（罗利克，P.（1976年）《自然》263，789 - 791）。
