Wolf D E
Biochemistry. 1985 Jan 29;24(3):582-6. doi: 10.1021/bi00324a006.
We have found that 2,4,6-trinitrobenzenesulfonate (TNBS) is an effective quencher of the fluorescence of the 1,1'-dialkyl-3,3,3',3'-tetramethylindocarbocyanines (CNdiI's). This quenching appears to occur by complex formation rather than a collisional mechanism. By use of this quenching, we have studied the transbilayer asymmetry of CNdiI labeling for large unilamellar membranes of egg phosphatidylcholine and the plasma membranes of human red blood cells and of ram epididymal spermatozoa. When CNdiI is added to membranes by ethanolic injection, only the outer leaflet labels. We have further shown that in large unilamellar vesicles of egg phosphatidylcholine, the CNdiI's do not appreciably "flip-flop" to the inner leaflet for at least 4 h at temperatures between 4 and 37 degrees C.
我们发现2,4,6-三硝基苯磺酸酯（TNBS）是1,1'-二烷基-3,3,3',3'-四甲基吲哚羰花青（CNdiI's）荧光的有效猝灭剂。这种猝灭似乎是通过形成复合物而非碰撞机制发生的。利用这种猝灭作用，我们研究了CNdiI在卵磷脂酰胆碱大单层膜、人红细胞质膜和公羊附睾精子质膜上的跨膜不对称性。当通过乙醇注射将CNdiI添加到膜中时，只有外层小叶被标记。我们进一步表明，在卵磷脂酰胆碱的大单层囊泡中，在4至37摄氏度之间的温度下，CNdiI至少4小时内不会明显“翻转”到内层小叶。
