Hildebrand Peter Werner, Preissner Robert, Frömmel Cornelius
Institute of Biochemistry Charité, Medical Faculty of the Humboldt University, Monbijoustrasse 2a, 10117 Berlin, Germany.
FEBS Lett. 2004 Feb 13;559(1-3):145-51. doi: 10.1016/S0014-5793(04)00061-4.
A total of 160 transmembrane helices of 15 non-homologous high-resolution X-ray protein structures have been analyzed in respect of their structural features. The dihedral angles and hydrogen bonds of the helical sections that span the hydrophobic interior of the lipid bilayer have been investigated. The Ramachandran plot of protein channels and solute transporters exhibit a significant shift Delta (phi- and psi-angles) of Delta mean (+4.5 degrees and -5.4 degrees ), compared to a reference group of 151 alpha-helices of the same average length derived from water-soluble globular proteins. At the C-termini of transmembrane helices structural motifs equivalent to the Gly-caps of helices in globular proteins have been found, with two third of the transmembrane Gly-caps taking up a primary structure that is typically not found at helix termini exposed to a polar solvent. The structural particularities reported here are relevant for the three-dimensional modelling of membrane protein structures.
我们对15种非同源高分辨率X射线蛋白质结构中的160个跨膜螺旋的结构特征进行了分析。研究了跨越脂质双分子层疏水内部的螺旋片段的二面角和氢键。与来自水溶性球状蛋白质的151个平均长度相同的α螺旋参考组相比，蛋白质通道和溶质转运体的拉氏图显示出显著的位移Delta（φ角和ψ角），Delta平均值为（+4.5度和-5.4度）。在跨膜螺旋的C末端，发现了与球状蛋白质中螺旋的Gly帽等效的结构基序，三分之二的跨膜Gly帽具有通常在暴露于极性溶剂的螺旋末端未发现的一级结构。这里报道的结构特殊性与膜蛋白结构的三维建模相关。
