ニュース

「Biophysics and Physicobiology」に Tetsuichi Wazawa, Takeharu Nagai による "Joule heating involving ion currents through channel proteins" をJ-STAGEの早期公開版として掲載

2023年06月28日 学会誌

日本生物物理学会欧文誌[Biophysics and Physicobiology]に以下の論文が早期公開されました。

Tetsuichi Wazawa, Takeharu Nagai
"Joule heating involving ion currents through channel proteins"

URL:https://doi.org/10.2142/biophysico.bppb-v20.0030


Large Image

Abstract
Ion currents associated with channel proteins in the presence of membrane potential are ubiquitous in cellular and organelle membranes. When an ion current occurs through a channel protein, Joule heating should occur. However, this Joule heating seems to have been largely overlooked in biology. Here we show theoretical investigation of Joule heating involving channel proteins in biological processes. We used electrochemical potential to derive the Joule’s law for an ion current through an ion transport protein in the presence of membrane potential, and we suggest that heat production and absorption can occur. Simulation of temperature distribution around a single channel protein with the Joule heating revealed that the temperature increase was as small as <10−3 K, although an ensemble of channel proteins was suggested to exhibit a noticeable temperature increase. Thereby, we theoretically investigated the Joule heating of systems containing ensembles of channel proteins. Nerve is known to undergo rapid heat production followed by heat absorption during the action potential, and our simulation of Joule heating for a squid giant axon combined with the Hodgkin-Huxley model successfully reproduced the feature of the heat. Furthermore, we extended the theory of Joule heating to uncoupling protein 1 (UCP1), a solute carrier family transporter, which is important to the non-shivering thermogenesis in brown adipose tissue mitochondria (BATM). Our calculations showed that the Joule heat involving UCP1 was comparable to the literature calorimetry data of BATM. Joule heating of ion transport proteins is likely to be one of important mechanisms of cellular thermogenesis.

URL: https://doi.org/10.2142/biophysico.bppb-v20.0030



前のページに戻る