His-Trp cation-π interaction and its structural role in an α-helical dimer of HIV-1 Vpr protein
His-Trp cation-π interaction and its structural role in an α-helical dimer of HIV-1 Vpr protein
复制标题
DOI：
10.1016/j.bpc.2013.01.004
复制
发表时间：
2013-03-01
影响因子：
3.8
通讯作者：
Takeuchi, Hideo
中科院分区：
文献类型：
--
作者：
Kamiyama, Takayuki;Miura, Takashi;Takeuchi, Hideo
Vpr是HIV-1病毒的一种多功能辅助蛋白，先前提出Vpr为反平行螺旋二聚体，不同亚基的第三个螺旋H-III相互面向。在这项研究中，我们通过使用片段肽Vpr52-80，跨越希尔区检查了反平行二聚体的结构和稳定性。目前对荧光、圆二色性和紫外吸收光谱的分析表明，质子化的His71和位于两个反平行螺旋两端附近的Trp54之间发生了阳离子- π相互作用。阳离子- π相互作用引起H-III螺旋的小伸长，增加了螺旋二聚体的热稳定性，并改变了螺旋排列以产生更紧凑的形式。His71-Trp54阳离子- π相互作用可用于稳定和调节Vpr的二聚体结构，以实现与其他蛋白质的适当相互作用。(C) 2013 Elsevier B.V.版权所有
Vpr is a multifunctional accessory protein of HIV-1 virus and was previously proposed to assume an antiparallel helical dimer with the third helices H-III of different subunits facing each other. In this study, we have examined the structure and stability of the antiparallel dimer by using a fragment peptide, Vpr52-80, spanning the Hill region. The present analyses of fluorescence, circular dichroism, and UV absorption spectra have shown that a cation-pi interaction takes place between protonated His71 and Trp54 located near the opposite ends of the two antiparallel helices. The cation-pi interaction induces a small elongation of the H-III helix, an increase in thermal stability of the helical dimer, and a modification of the helix arrangement to produce a more compact form. The His71-Trp54 cation-pi interaction may be utilized in stabilizing and tuning the dimeric structure of Vpr to achieve proper interactions with other proteins. (C) 2013 Elsevier B.V. All rights reserved.