Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas, 72701, USA.
Chembiochem. 2016 Mar 15;17(6):462-5. doi: 10.1002/cbic.201500656. Epub 2016 Feb 10.
Transmembrane helices of integral membrane proteins often are flanked by interfacial aromatic residues that can serve as anchors to aid the stabilization of a tilted transmembrane orientation. Yet, physical factors that govern the orientation or dynamic averaging of individual transmembrane helices are not well understood and have not been adequately explained. Using solid-state (2) H NMR spectroscopy to examine lipid bilayer-incorporated model peptides of the GWALP23 (acetyl-GGALW(LA)6 LWLAGA-amide) family, we observed substantial unwinding at the terminals of several tilted helices spanning the membranes of DLPC, DMPC, or DOPC lipid bilayers. The fraying of helix ends might be vital for defining the dynamics and orientations of transmembrane helices in lipid bilayer membranes.
整合膜蛋白的跨膜螺旋通常被界面芳香族残基包围，这些残基可以作为锚定物来帮助稳定倾斜的跨膜取向。然而，控制单个跨膜螺旋取向或动态平均的物理因素尚未得到很好的理解，也没有得到充分的解释。我们使用固态 (2) H NMR 光谱法研究 GWALP23（乙酰-GGALW(LA)6 LWLAGA-酰胺）家族的脂质双层嵌入模型肽，观察到在跨越 DLPC、DMPC 或 DOPC 脂质双层膜的几个倾斜螺旋的末端存在大量解旋。螺旋末端的磨损对于定义脂质双层膜中跨膜螺旋的动力学和取向可能至关重要。
