Chou James J, Kaufman Joshua D, Stahl Stephen J, Wingfield Paul T, Bax Ad
Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA.
J Am Chem Soc. 2002 Mar 20;124(11):2450-1. doi: 10.1021/ja017875d.
The structure of a water-insoluble fragment encompassing residues 282-304 of the HIV envelope protein gp41 is studied when solubilized by dihexanoyl phosphatidylcholine (DHPC) and by small bicelles, consisting of a 4:1 molar ratio of DHPC and dimyristoyl phosphatidylcholine (DMPC). Weak alignment with the magnetic field was accomplished in a stretched polyacrylamide gel, permitting measurement of one-bond (1)H-(15)N, (13)Ca-(13)C', and (13)C'-(15)N dipolar couplings, which formed the basis for determining the peptide structure. In both detergent systems, the peptide adopts an alpha-helical conformation from residue 4 through 18. In the presence of the DHPC micelles the helix is strongly curved towards the hydrophobic surface, whereas in the presence of bicelles a much weaker curvature in the opposite direction is observed.
研究了HIV包膜蛋白gp41中包含282 - 304位残基的水不溶性片段在被二己酰磷脂酰胆碱（DHPC）和由摩尔比为4:1的DHPC与二肉豆蔻酰磷脂酰胆碱（DMPC）组成的小双分子层溶解时的结构。在拉伸聚丙烯酰胺凝胶中实现了与磁场的弱排列，从而能够测量一键（1）H - （15）N、（13）Ca - （13）C'和（13）C' - （15）N偶极耦合，这些耦合构成了确定肽结构的基础。在两种去污剂体系中，该肽从第4位残基到第18位残基均采用α - 螺旋构象。在DHPC胶束存在下，螺旋强烈地向疏水表面弯曲，而在双分子层存在下，则观察到相反方向的弱得多的弯曲。
