Biophysics and Physicobiology最新文献_第3页

Solid-state NMR for the characterization of retinal chromophore and Schiff base in TAT rhodopsin embedded in membranes under weakly acidic conditions. 固态核磁共振用于表征弱酸性条件下嵌入膜中的 TAT rhodopsin 中的视网膜发色团和希夫碱。

Biophysics and Physicobiology Pub Date : 2023-03-02 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s017

Sui Arikawa, Teppei Sugimoto, Takashi Okitsu, Akimori Wada, Kota Katayama, Hideki Kandori, Izuru Kawamura

{"title":"Solid-state NMR for the characterization of retinal chromophore and Schiff base in TAT rhodopsin embedded in membranes under weakly acidic conditions.","authors":"Sui Arikawa, Teppei Sugimoto, Takashi Okitsu, Akimori Wada, Kota Katayama, Hideki Kandori, Izuru Kawamura","doi":"10.2142/biophysico.bppb-v20.s017","DOIUrl":"10.2142/biophysico.bppb-v20.s017","url":null,"abstract":"TAT rhodopsin extracted from the marine bacterium SAR11 HIMB114 has a characteristic Thr-Ala-Thr motif and contains both protonated and deprotonated states of Schiff base at physiological pH conditions due to the low pKa. Here, using solid-state NMR spectroscopy, we investigated the 13C and 15N NMR signals of retinal in only the protonated state of TAT in the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine/1-palmitoyl-2-oleoyl-sn-glycero-3-phospho (1'-rac-glycerol) (POPE/POPG) membrane at weakly acidic conditions. In the 13C NMR spectrum of 13C retinal-labeled TAT rhodopsin, the isolated 14-13C signals of 13-trans/15-anti and 13-cis/15-syn isomers were observed at a ratio of 7:3. 15N retinal protonated Schiff base (RPSB) had a significantly higher magnetic field resonance at 160 ppm. In 15N RPSB/λmax analysis, the plot of TAT largely deviated from the trend based on the retinylidene-halide model compounds and microbial rhodopsins. Our findings indicate that the RPSB of TAT forms a very weak interaction with the counterion.","PeriodicalId":8976,"journal":{"name":"Biophysics and Physicobiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10865839/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88200024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Function of animal rhodopsins and related proteins: Report for the session 9. 动物 rhodopsins 和相关蛋白的功能：第 9 次会议报告。

Biophysics and Physicobiology Pub Date : 2023-03-02 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s018

Hiroo Imai, Akihisa Terakita

引用次数: 0

Optogenetics II, sponsored by JST: Report for the session 13. 光遗传学 II，由 JST 赞助：会议报告 13.

Biophysics and Physicobiology Pub Date : 2023-03-02 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s020

Hiroo Imai, Hideki Kandori

引用次数: 0

Functional diversity and evolution in animal rhodopsins: Report for the session 11. 动物犀角蛋白的功能多样性和进化：第 11 次会议报告。

Biophysics and Physicobiology Pub Date : 2023-03-02 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s019

Hiroo Imai, Hideki Kandori

引用次数: 0

Protein dynamics of a light-driven Na⁺ pump rhodopsin probed using a tryptophan residue near the retinal chromophore. 利用视网膜发色团附近的色氨酸残基探测光驱动 Na+ 泵视网膜红蛋白的蛋白质动力学。

Biophysics and Physicobiology Pub Date : 2023-02-25 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s016

Akihiro Otomo, Misao Mizuno, Keiichi Inoue, Hideki Kandori, Yasuhisa Mizutani

{"title":"Protein dynamics of a light-driven Na+ pump rhodopsin probed using a tryptophan residue near the retinal chromophore.","authors":"Akihiro Otomo, Misao Mizuno, Keiichi Inoue, Hideki Kandori, Yasuhisa Mizutani","doi":"10.2142/biophysico.bppb-v20.s016","DOIUrl":"10.2142/biophysico.bppb-v20.s016","url":null,"abstract":"Direct observation of protein structural changes during ion transport in ion pumps provides valuable insights into the mechanism of ion transport. In this study, we examined structural changes in the light-driven sodium ion (Na+) pump rhodopsin KR2 on the sub-millisecond time scale, corresponding with the uptake and release of Na+. We compared the ion-pumping activities and transient absorption spectra of WT and the W215F mutant, in which the Trp215 residue located near the retinal chromophore on the cytoplasmic side was replaced with a Phe residue. Our findings indicated that atomic contacts between the bulky side chain of Trp215 and the C20 methyl group of the retinal chromophore promote relaxation of the retinal chromophore from the 13-cis to the all-trans form. Since Trp215 is conserved in other ion-pumping rhodopsins, the present results suggest that this residue commonly acts as a mechanical transducer. In addition, we measured time-resolved ultraviolet resonance Raman (UVRR) spectra to show that the environment around Trp215 becomes less hydrophobic at 1 ms after photoirradiation and recovers to the unphotolyzed state with a time constant of around 10 ms. These time scales correspond to Na+ uptake and release, suggesting evolution of a transient ion channel at the cytoplasmic side for Na+ uptake, consistent with the alternating-access model of ion pumps. The time-resolved UVRR technique has potential for application to other ion-pumping rhodopsins and could provide further insights into the mechanism of ion transport.","PeriodicalId":8976,"journal":{"name":"Biophysics and Physicobiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10865881/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83647211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Introduction of Session 8, "Structural mechanism of animal rhodopsins and GPCR". 介绍第八讲 "动物犀牛蛋白和 GPCR 的结构机制"。

Biophysics and Physicobiology Pub Date : 2023-02-22 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s015

Takeshi Murata

引用次数: 0

Recent advances in biological rhythm and non-visual photoreception: Report for the session 10 at the 19th International Conference on Retinal Proteins. 生物节律和非视觉光感的最新进展：第 19 届视网膜蛋白质国际会议第 10 次会议报告。

Biophysics and Physicobiology Pub Date : 2023-02-21 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s013

Yoshitaka Fukada

引用次数: 0

Structural mechanism of microbial rhodopsins: Report for the session 4 at the 19^th International Conference on Retinal Proteins. 微生物视网膜蛋白的结构机制：第 19 届视网膜蛋白质国际会议第 4 次会议报告。

Biophysics and Physicobiology Pub Date : 2023-02-21 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s014

Tsutomu Kouyama, Norbert A Dencher

引用次数: 0

Introduction of Session 7, "Functional diversity and evolution in microbial rhodopsins". 会议 7 "微生物荷尔蒙蛋白的功能多样性和进化 "介绍。

Biophysics and Physicobiology Pub Date : 2023-02-09 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s012

Takeshi Murata

引用次数: 0

Potassium-selective channelrhodopsins. 钾选择性通道发光素。

Biophysics and Physicobiology Pub Date : 2023-02-04 eCollection Date: 2023-03-21 DOI: 10.2142/biophysico.bppb-v20.s011

Elena G Govorunova, Oleg A Sineshchekov, John L Spudich

{"title":"Potassium-selective channelrhodopsins.","authors":"Elena G Govorunova, Oleg A Sineshchekov, John L Spudich","doi":"10.2142/biophysico.bppb-v20.s011","DOIUrl":"10.2142/biophysico.bppb-v20.s011","url":null,"abstract":"Since their discovery 21 years ago, channelrhodopsins have come of age and have become indispensable tools for optogenetic control of excitable cells such as neurons and myocytes. Potential therapeutic utility of channelrhodopsins has been proven by partial vision restoration in a human patient. Previously known channelrhodopsins are either proton channels, non-selective cation channels almost equally permeable to Na+ and K+ besides protons, or anion channels. Two years ago, we discovered a group of channelrhodopsins that exhibit over an order of magnitude higher selectivity for K+ than for Na+. These proteins, known as \"kalium channelrhodopsins\" or KCRs, lack the canonical tetrameric selectivity filter found in voltage- and ligand-gated K+ channels, and use a unique selectivity mechanism intrinsic to their individual protomers. Mutant analysis has revealed that the key residues responsible for K+ selectivity in KCRs are located at both ends of the putative cation conduction pathway, and their role has been confirmed by high-resolution KCR structures. Expression of KCRs in mouse neurons and human cardiomyocytes enabled optical inhibition of these cells' electrical activity. In this minireview we briefly discuss major results of KCR research obtained during the last two years and suggest some directions of future research.","PeriodicalId":8976,"journal":{"name":"Biophysics and Physicobiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10865875/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85676750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0