TY - JOUR
T1 - His-Trp cation-π interaction and its structural role in an α-helical dimer of HIV-1 Vpr protein
AU - Kamiyama, Takayuki
AU - Miura, Takashi
AU - Takeuchi, Hideo
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for Scientific Research (B) ( 23390008 ) from the Japan Society for the Promotion of Science .
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/3
Y1 - 2013/3
N2 - Vpr is a multifunctional accessory protein of HIV-1 virus and was previously proposed to assume an antiparallel helical dimer with the third helices HIII 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 HIII region. The present analyses of fluorescence, circular dichroism, and UV absorption spectra have shown that a cation-π interaction takes place between protonated His71 and Trp54 located near the opposite ends of the two antiparallel helices. The cation-π interaction induces a small elongation of the HIII 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-π interaction may be utilized in stabilizing and tuning the dimeric structure of Vpr to achieve proper interactions with other proteins.
AB - Vpr is a multifunctional accessory protein of HIV-1 virus and was previously proposed to assume an antiparallel helical dimer with the third helices HIII 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 HIII region. The present analyses of fluorescence, circular dichroism, and UV absorption spectra have shown that a cation-π interaction takes place between protonated His71 and Trp54 located near the opposite ends of the two antiparallel helices. The cation-π interaction induces a small elongation of the HIII 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-π interaction may be utilized in stabilizing and tuning the dimeric structure of Vpr to achieve proper interactions with other proteins.
KW - Cation-π interaction
KW - Circular dichroism
KW - Fluorescence
KW - HIV-1
KW - Keywords
KW - UV absorption
KW - Vpr protein
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U2 - 10.1016/j.bpc.2013.01.004
DO - 10.1016/j.bpc.2013.01.004
M3 - Article
C2 - 23467037
AN - SCOPUS:84874431675
VL - 173-174
SP - 8
EP - 14
JO - Biophysical Chemistry
JF - Biophysical Chemistry
SN - 0301-4622
ER -
