Nilsson I, von Heijne G
Department of Biochemistry, Stockholm University, Stockholm, S-106 91, Sweden.
J Mol Biol. 1998 Dec 11;284(4):1185-9. doi: 10.1006/jmbi.1998.2219.
We have constructed model membrane proteins with hydrophobic segments of the general composition Leu29Val-Leun where n=10 and 20, and have analyzed their transmembrane topology when inserted into microsomal membranes. These hydrophobic segments span the membrane once, even though they are twice as long as normal transmembrane helices. Strikingly, a single proline residue introduced near the center of the Leu39Val hydrophobic stretch induces the formation of two transmembrane segments separated by a tight turn. These results have implications for our understanding of membrane protein assembly in the endoplasmic reticulum, and for the development of techniques for predicting membrane protein topology.
我们构建了具有一般组成Leu29Val-Leun疏水片段的模型膜蛋白，其中n = 10和20，并分析了它们插入微粒体膜时的跨膜拓扑结构。这些疏水片段虽然比正常跨膜螺旋长两倍，但仍能跨膜一次。引人注目的是，在Leu39Val疏水片段中心附近引入的单个脯氨酸残基会诱导形成由紧密转角隔开的两个跨膜片段。这些结果对我们理解内质网中膜蛋白的组装以及预测膜蛋白拓扑结构的技术发展具有启示意义。
