Biron E, Voyer N, Meillon J C, Cormier M E, Auger M
Département de chimie and Centre de recherche sur la fonction, la structure et l'ingénierie des protéines, Faculté des sciences et de génie, Université Laval, Québec, Québec, Canada G1K 7P4.
Biopolymers. 2000;55(5):364-72. doi: 10.1002/1097-0282(2000)55:5<364::AID-BIP1010>3.0.CO;2-Z.
The conformational and orientation studies in lipid bilayers of 21 amino acid peptides bearing six crown ethers are reported. The compounds were designed to form artificial ion channels by stacking the crown rings, and were shown to be functional in bilayer membranes. We used Fourier transform infrared spectroscopy and CD spectropolarimetry to study the conformation of the peptides in solution and in lipid bilayers. These studies revealed that hexacrown peptides retain their alpha-helical conformation when incorporated in a lipid bilayer environment. Attenuated total reflectance spectroscopy was used to investigate the orientation of the peptides in a lipid bilayer. Results demonstrated that the peptides are not oriented at a fixed angle in membrane, but rather are in incorporation equilibrium between an active state parallel to the lipid chain and an inactive state adsorbed at the surface of the bilayer. From these results, we propose a model for the channel activity and the gating mechanism of these hexacrown peptides in bilayer membranes.
报道了对带有六个冠醚的21个氨基酸肽在脂质双层中的构象和取向研究。这些化合物被设计通过堆叠冠环形成人工离子通道，并已证明在双层膜中具有功能。我们使用傅里叶变换红外光谱和圆二色光谱偏振法研究肽在溶液中和脂质双层中的构象。这些研究表明，六冠肽在掺入脂质双层环境时保持其α-螺旋构象。采用衰减全反射光谱研究肽在脂质双层中的取向。结果表明，肽在膜中不是以固定角度取向，而是在与脂质链平行的活性状态和吸附在双层表面的非活性状态之间处于掺入平衡。基于这些结果，我们提出了一个关于这些六冠肽在双层膜中的通道活性和门控机制的模型。
