TY - JOUR
T1 - Zn2+-Binding to the Voltage-Gated Proton Channel Hv1/VSOP
AU - Iwaki, Masayo
AU - Takeshita, Kohei
AU - Kondo, Hiroko X.
AU - Kinoshita, Kengo
AU - Okamura, Yasushi
AU - Takano, Yu
AU - Nakagawa, Atsushi
AU - Kandori, Hideki
N1 - Funding Information:
This work is supported by JST CREST Grant Number JPMJCR14M3 and PRESTO, JST, and Platform Project for Supporting Drug Discovery and Life Science Research (Basis for Supporting Innovative Drug Discovery and Life Science Research (BINDS)) from AMED under Grant Number JP18am0101067. Computational resources were provided in part by RIKEN Advanced Center for Computing and Communication. We would like to thank Dr. Yusuke Kanematsu and Dr. Takao Otsuka for useful discussions.
Publisher Copyright:
Copyright © 2018 American Chemical Society.
PY - 2018/10/4
Y1 - 2018/10/4
N2 - The voltage-gated proton channel (Hv1/VSOP) is inhibited by Zn2+, of which the binding site is located in the extracellular region. We utilized attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy to examine the coordination structure by monitoring protein structural changes induced by Zn2+-binding. The Zn2+-induced difference ATR-FTIR spectra of Hv1 showed IR features that can be assigned to the histidine C5-N1 and carboxylate-COO- stretches as well as amide I changes likely in α-helical peptide bonds. Analysis of vibrational frequencies indicated that the Zn2+ is coordinated by the anionic carboxylate with monodentate mode and by the histidine at N1 (Nτ) position of the neutral imidazole form. Combined with quantum chemical calculations, the most probable coordination structure was proposed as a tetrahedral geometry with ligands of carboxylate and imidazole groups in addition to a water molecule.
AB - The voltage-gated proton channel (Hv1/VSOP) is inhibited by Zn2+, of which the binding site is located in the extracellular region. We utilized attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy to examine the coordination structure by monitoring protein structural changes induced by Zn2+-binding. The Zn2+-induced difference ATR-FTIR spectra of Hv1 showed IR features that can be assigned to the histidine C5-N1 and carboxylate-COO- stretches as well as amide I changes likely in α-helical peptide bonds. Analysis of vibrational frequencies indicated that the Zn2+ is coordinated by the anionic carboxylate with monodentate mode and by the histidine at N1 (Nτ) position of the neutral imidazole form. Combined with quantum chemical calculations, the most probable coordination structure was proposed as a tetrahedral geometry with ligands of carboxylate and imidazole groups in addition to a water molecule.
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U2 - 10.1021/acs.jpcb.8b04890
DO - 10.1021/acs.jpcb.8b04890
M3 - Article
C2 - 30204443
AN - SCOPUS:85054143946
SN - 1520-6106
VL - 122
SP - 9076
EP - 9080
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 39
ER -