Vranken W F, Budesinsky M, Martins J C, Fant F, Boulez K, Gras-Masse H, Borremans F A
Department of Organic Chemistry, University of Gent, Belgium.
Eur J Biochem. 1996 Feb 15;236(1):100-8. doi: 10.1111/j.1432-1033.1996.00100.x.
The disulfide-bridge-closed cyclic peptide corresponding to the whole V3 loop of the RF HIV-1 strain was examined by proton two-dimensional NMR spectroscopy in water and water/trifluoroethanol solutions. Although most of the peptide is conformationally averaged in water, the NOE data support a beta-turn conformation for the central conservative GPGR region and the presence of nascent helix. Upon addition of trifluoroethanol, helix formation in the C-terminal part becomes apparent. This is confirmed by CD data. NOEs indicative of multiple and transient beta-turns around the Asn6 glycosylation site and NOEs fitting X-ray data on a linear V3 peptide-Fab complex also emerge. The C-terminal helix is shown to have amphipathic character and might thus assist in the infection process.
通过质子二维核磁共振光谱法，在水和水/三氟乙醇溶液中对与RF HIV-1毒株整个V3环相对应的二硫键封闭环肽进行了研究。尽管该肽在水中大多呈构象平均化状态，但NOE数据支持中央保守的GPGR区域具有β-转角构象以及新生螺旋的存在。加入三氟乙醇后，C端部分的螺旋形成变得明显。这得到了圆二色光谱数据的证实。围绕Asn6糖基化位点的多个瞬时β-转角的指示性NOE以及符合线性V3肽-Fab复合物X射线数据的NOE也出现了。C端螺旋显示具有两亲性特征，因此可能有助于感染过程。
