Kusumi A, Hyde J S
Biochemistry. 1982 Nov 9;21(23):5978-83. doi: 10.1021/bi00266a039.
Rotational diffusion of rhodopsin in reconstituted membranes of phosphatidylcholines of various alkyl chain lengths has been measured by using saturation-transfer electron spin resonance spectroscopy as a function of temperature and lipid/rhodopsin mole ratio. For dipalmitoyl-phosphatidylcholine, the rotational correlation time is 20 microseconds at physiological concentration, the same as in rod outer segment (ros) membranes. Dilution reduces the time to 10 microseconds, a value that is ascribed to well-dispersed monomeric rhodopsin. Use of phospholipids with longer or shorter chains results in sharply increased rotational correlation times. It is concluded that rhodopsin molecules are transiently associated in both reconstituted and ros membranes and that the nature of the association is determined by lipid type and composition.
利用饱和转移电子自旋共振光谱法，测量了不同烷基链长度的磷脂酰胆碱重构膜中视紫红质的旋转扩散随温度和脂质/视紫红质摩尔比的变化。对于二棕榈酰磷脂酰胆碱，在生理浓度下旋转相关时间为20微秒，与视杆外段（ros）膜中的相同。稀释会将时间缩短至10微秒，该值归因于分散良好的单体视紫红质。使用链长更长或更短的磷脂会导致旋转相关时间急剧增加。得出的结论是，视紫红质分子在重构膜和ros膜中都是瞬时缔合的，并且缔合的性质由脂质类型和组成决定。
