Smith D D, Selman B R, Voegeli K K, Johnson G, Dilley R A
Biochim Biophys Acta. 1977 Mar 11;459(3):468-82. doi: 10.1016/0005-2728(77)90046-9.
Intact grana and stroma membranes (outer membrane absent) and detergent or sonication disrupted thylakoid membranes were treated with the hydrophilic covalent chemical modifiers [35S]diazonium benzene sulfonic acid ([35S]DABS) and [14C]glycine ethylester plus 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide metho-p-toluenesulfonate (CDIS). Plastocyanin was purified using column chromatography followed by polyacrylamide gel electrophoresis and the incorporation of [35S]DABS and [14C]glycine ethylester into plastocyanin was determined by slicing the gels and counting the radioactivity in the plastocyanin band. Plastocyanin isolated from thylakoids disrupted prior to chemical modification binds two to four times as much of either modifier than the plastocyanin isolated from intact chloroplasts. This ratio is five to ten times lower than the ratio expected for a component buried behind the permeability barrier of a membrane. The data suggest that plastocyanin is partially exposed at the external surface of the thylakoid membrane rather than being completely buried in, or behind, the lipo-protein membrane.
完整的基粒和基质膜（外膜缺失）以及经去污剂或超声处理破坏的类囊体膜，用亲水性共价化学修饰剂[35S]重氮苯磺酸（[35S]DABS）和[14C]甘氨酸乙酯加1 - 环己基 - 3 -（2 - 吗啉代乙基）- 碳二亚胺对甲苯磺酸盐（CDIS）进行处理。使用柱色谱法随后进行聚丙烯酰胺凝胶电泳纯化质体蓝素，并通过切割凝胶并计数质体蓝素条带中的放射性来确定[35S]DABS和[14C]甘氨酸乙酯掺入质体蓝素的情况。与从完整叶绿体中分离的质体蓝素相比，在化学修饰之前从破坏的类囊体中分离的质体蓝素结合的两种修饰剂中的任何一种的量要多两到四倍。该比例比预期埋在膜的渗透屏障后面的组分的比例低五到十倍。数据表明质体蓝素部分暴露在类囊体膜的外表面，而不是完全埋在脂蛋白膜中或其后面。
