Soubias Olivier, Teague Walter E, Gawrisch Klaus
Laboratory of Membrane Biochemistry and Biophysics, NIAAA, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Biol Chem. 2006 Nov 3;281(44):33233-41. doi: 10.1074/jbc.M603059200. Epub 2006 Sep 7.
The interaction of bovine rhodopsin with poly- and monounsaturated lipids was studied by (1)H MAS NMR with magnetization transfer from rhodopsin to lipid. Experiments were conducted on bovine rod outer segment (ROS) disks and on recombinant membranes containing lipids with polyunsaturated, docosahexaenoyl (DHA) chains. Poly- and monounsaturated lipids interact specifically with different sites on the rhodopsin surface. Rates of magnetization transfer from protein to DHA are lipid headgroup-dependent and increased in the sequence PC < PS < PE. Boundary lipids are in fast exchange with the lipid matrix on a time scale of milliseconds or shorter. All rhodopsin photointermediates transferred magnetization preferentially to DHA-containing lipids, but highest rates were observed for Meta-III rhodopsin. The experiments show clearly that the surface of rhodopsin has sites for specific interaction with lipids. Current theories of lipid-protein interaction do not account for such surface heterogeneity.
通过将磁化从视紫红质转移至脂质的¹H MAS NMR研究了牛视紫红质与多不饱和及单不饱和脂质的相互作用。实验在牛视杆外段（ROS）盘以及含有多不饱和二十二碳六烯酰基（DHA）链脂质的重组膜上进行。多不饱和及单不饱和脂质与视紫红质表面的不同位点发生特异性相互作用。从蛋白质到DHA的磁化转移速率取决于脂质头部基团，且在PC < PS < PE序列中增加。边界脂质在毫秒或更短的时间尺度上与脂质基质进行快速交换。所有视紫红质光中间体优先将磁化转移至含DHA的脂质，但在Meta-III视紫红质中观察到最高速率。实验清楚地表明视紫红质表面存在与脂质特异性相互作用的位点。当前脂质-蛋白质相互作用理论无法解释这种表面异质性。
