著者

Izuru Kawamura Hayato Seki Seiya Tajima Yoshiteru Makino Arisu Shigeta Takashi Okitsu Akimori Wada Akira Naito Yuki Sudo

出版者

The Biophysical Society of Japan

雑誌

Biophysics and Physicobiology (ISSN:21894779)

巻号頁・発行日

vol.18, pp.177-185, 2021 (Released:2021-08-07)

参考文献数

53

被引用文献数

6

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Middle rhodopsin (MR) found from the archaeon Haloquadratum walsbyi is evolutionarily located between two different types of rhodopsins, bacteriorhodopsin (BR) and sensory rhodopsin II (SRII). Some isomers of the chromophore retinal and the photochemical reaction of MR are markedly different from those of BR and SRII. In this study, to obtain the structural information regarding its active center (i.e., retinal), we subjected MR embedded in lipid bilayers to solid-state magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy. The analysis of the isotropic 13C chemical shifts of the retinal chromophore revealed the presence of three types of retinal configurations of dark-adapted MR: (13-trans, 15-anti (all-trans)), (13-cis, 15-syn), and 11-cis isomers. The higher field resonance of the 20-C methyl carbon in the all-trans retinal suggested that Trp182 in MR has an orientation that is different from that in other microbial rhodopsins, owing to the changes in steric hindrance associated with the 20-C methyl group in retinal. 13Cζ signals of Tyr185 in MR for all-trans and 13-cis, 15-syn isomers were discretely observed, representing the difference in the hydrogen bond strength of Tyr185. Further, 15N NMR analysis of the protonated Schiff base corresponding to the all-trans and 13-cis, 15-syn isomers in MR showed a strong electrostatic interaction with the counter ion. Therefore, the resulting structural information exhibited the property of stable retinal conformations of dark-adapted MR.

著者

Izuru Kawamura Hayato Seki Seiya Tajima Yoshiteru Makino Arisu Shigeta Takashi Okitsu Akimori Wada Akira Naito Yuki Sudo

出版者

The Biophysical Society of Japan

雑誌

Biophysics and Physicobiology (ISSN:21894779)

巻号頁・発行日

pp.bppb-v18.019, (Released:2021-07-14)

被引用文献数

6

著者

AKIRA NAITO MICHIHIRO YAJIMA HIDEHIKO FUKAMACHI KOJI USHIKOSHI YING-JIE SUN YOSHIFUSA SHIMIZU

出版者

東北ジャーナル刊行会

雑誌

The Tohoku Journal of Experimental Medicine (ISSN:00408727)

巻号頁・発行日

vol.175, no.4, pp.285-288, 1995 (Released:2006-08-31)

参考文献数

13

被引用文献数

4 10

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NAITO, A., YAJIMA, M., FUKAMACHI, H., USHIKOSHI, K., SUN, Y.-J. and SHIMIZU, Y. Electromyographic (EMG) Study of the Elbow Flexors during Supination and Pronation of the Forearm. Tohoku J. Exp. Med., 1995, 175 (4), 285-288 - Activities of the elbow flexors during supination and pronation of the forearm in a normal human volunteer were studied by an electromyography (EMG). The volunteer performed the movement slowly or quickly holding elbow flexion at various angles with or without a load. The biceps brachii showed an increase and a decrease of EMG activities during supination and pronation, respectively. The brachialis and brachioradialis showed a reduction and an increment of EMU activities accompanied by an increase and a decrease of EMG activities in the biceps brachii, respectively. These findings seem to indicate that reciprocal contractions among the elbow flexors permit the biceps brachii to work for supination without an induction of elbow flexion.