Zumbulyadis N, O'Brien D F
Biochemistry. 1979 Nov 27;18(24):5427-32. doi: 10.1021/bi00591a027.
Proton and carbon-13 nuclear magnetic resonance (1H and 13C NMR) spectra of rhodopsin-phospholipid membrane vesicles and sonicated disk membranes are presented and discussed. The presence of rhodopsin in egg phosphatidylcholine vesicles results in homogeneous broadening of the methylene and methyl resonances. This effect is enhanced with increasing rhodopsin content and decreased by increasing temperature. The proton NMR data indicate the phospholipid molecules exchange rapidly (less than 10(-3) s) between the bulk membrane lipid and the lipid in the immediate proximity of the rhodopsin. These interactions result in a reduction in either or both the frequency and amplitude of the tilting motion of the acyl chains. The 13C NMR spectra identify the acyl chains and the glycerol backbone as the major sites of protein lipid interaction. In the disk membranes the saturated sn-1 acyl chain is significantly more strongly immobilized than the polyunsaturated sn-2 acyl chain. This suggest a membrane model in which the lipid molecules preferentially solvate the protein with the sn-1 chain, which we term an edge-on orientation. The NMR data on rhodopsin-asolectin membrane vesicles demonstrate that the lipid composition is not altered during reconstitution of the membranes from purified rhodopsin and lipids in detergent.
本文给出并讨论了视紫红质 - 磷脂膜囊泡和超声处理的盘状膜的质子和碳 - 13核磁共振（1H和13C NMR）光谱。视紫红质存在于卵磷脂囊泡中会导致亚甲基和甲基共振的均匀展宽。随着视紫红质含量增加，这种效应增强，而随着温度升高而减弱。质子NMR数据表明磷脂分子在整体膜脂质与视紫红质紧邻的脂质之间快速交换（小于10^(-3) s）。这些相互作用导致酰基链倾斜运动的频率和幅度降低，或两者同时降低。13C NMR光谱确定酰基链和甘油主链是蛋白质 - 脂质相互作用的主要位点。在盘状膜中，饱和的sn - 1酰基链比多不饱和的sn - 2酰基链固定得明显更强。这表明存在一种膜模型，其中脂质分子优先用sn - 1链溶剂化蛋白质，我们将其称为边缘取向。视紫红质 - 大豆卵磷脂膜囊泡的NMR数据表明，在从纯化的视紫红质和去污剂中的脂质重建膜的过程中，脂质组成没有改变。
