Vogel H, Nilsson L, Rigler R, Meder S, Boheim G, Beck W, Kurth H H, Jung G
Institute of Physical Chemistry, Federal Institute of Technology, Lausanne, Switzerland.
Eur J Biochem. 1993 Mar 1;212(2):305-13. doi: 10.1111/j.1432-1033.1993.tb17663.x.
Putative transmembrane helices of membrane proteins in general and channel proteins in particular often contain proline residues which may induce a bend into an otherwise regular helical structure. Here we show by fluorescence-energy-transfer measurements and molecular-dynamics calculations that, in the case of synthetic bilayer-spanning helical polypeptides, a proline-induced bend in a helix acts as a flexible element mediating rigid body motions of the helical segments. Most important, such structural fluctuations in the transmembrane helices seem to play a functional role in the formation of ionic channels in planar lipid bilayers and biological membranes.
一般来说，膜蛋白尤其是通道蛋白的推定跨膜螺旋通常含有脯氨酸残基，这些残基可能会使原本规则的螺旋结构发生弯曲。在这里，我们通过荧光能量转移测量和分子动力学计算表明，对于合成的跨双层螺旋多肽而言，螺旋中脯氨酸诱导的弯曲充当了介导螺旋段刚体运动的柔性元件。最重要的是，跨膜螺旋中的这种结构波动似乎在平面脂质双层和生物膜中离子通道的形成中发挥功能作用。
