Low-frequency dynamics of biological molecules studied by terahertz time-domain spectroscopy

Kawaguchi, Shintaro; Kambara, Ohki; Ponseca, Carlito S.; Shibata, Mikihiro; Kandori, Hideki; Tominaga, Keisuke

doi:10.1155/2010/536453

Cited by 5 publications

(1 citation statement)

References 4 publications

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“…Here, we conducted THz experiments on four liquid samples: GM (an aqueous solution comprising nutrients to support in vitro cell growth); an amiloride solution in GM; A6 cells’ suspension GM and A6 cells treated with amiloride in GM. The spectra comprised absorptions in the 0.18–1 THz frequency range, a region characteristic for low frequency, large amplitude motions of biomolecules [ 12 , 21 , 22 ]. The media in which cells were suspended, namely GM and GM + amiloride, present similar THz absorptions that increase monotonically with the frequency in the analyzed range, sustaining the hypothesis that amiloride does not change the absorption of the solute.…”

Section: Discussionmentioning

confidence: 99%

Epithelial Sodium Channel Inhibition by Amiloride Addressed with THz Spectroscopy and Molecular Modeling

et al. 2022

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THz spectroscopy is important for the study of ion channels because it directly addresses the low frequency collective motions relevant for their function. Here we used THz spectroscopy to investigate the inhibition of the epithelial sodium channel (ENaC) by its specific blocker, amiloride. Experiments were performed on A6 cells’ suspensions, which are cells overexpressing ENaC derived from Xenopus laevis kidney. THz spectra were investigated with or without amiloride. When ENaC was inhibited by amiloride, a substantial increase in THz absorption was noticed. Molecular modeling methods were used to explain the observed spectroscopic differences. THz spectra were simulated using the structural models of ENaC and ENaC—amiloride complexes built here. The agreement between the experiment and the simulations allowed us to validate the structural models and to describe the amiloride dynamics inside the channel pore. The amiloride binding site validated using THz spectroscopy agrees with previous mutagenesis studies. Altogether, our results show that THz spectroscopy can be successfully used to discriminate between native and inhibited ENaC channels and to characterize the dynamics of channels in the presence of their specific antagonist.

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Section: Discussionmentioning

confidence: 99%