Article
Multidisciplinary Sciences
Steven D. E. Fried, Kushani S. K. Hewage, Anna R. Eitel, Audrey Struts, Nipuna Weerasinghe, Suchithranga M. D. C. Perera, Michael F. Brown
Summary: Maltose activates rhodopsin and enters the protein bound to water, facilitating GPCR signaling. This study challenges the understanding of the role of water molecules in GPCR signaling mechanisms.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Biochemistry & Molecular Biology
Alexandra-Madelaine Tichy, Wang Lok So, Elliot J. Gerrard, Harald Janovjak
Summary: GPCRs are the largest human receptor family involved in various physiological processes. Researchers have optimized light-activated OptoXRs using structure-guided methods to improve signal coupling.
Review
Chemistry, Physical
Bianca Chandler, Lauren Todd, Steven O. Smith
Summary: G protein-coupled receptors (GPCRs) are a class of transmembrane proteins with a simple structure that can recognize diverse chemical signals. There are over 800 GPCRs encoded in the human genome, serving as receptors for vision, smell, taste, and other physiological processes. While protein crystallography and electron cryo-microscopy have provided high-resolution structures of GPCRs, the structural changes induced by ligand or drug binding to stabilize active or inactive conformations are often subtle. NMR spectroscopy can provide insights into the local structure, dynamics, and activation pathways of GPCRs, capturing intermediate states and low-population conformations. Solid-state magic angle spinning NMR has been used to study the structure and activation mechanisms of GPCRs, particularly in the diverse class A family. This review highlights the application of solid-state and solution-state NMR spectroscopy in understanding the activation of different GPCR classes and subfamilies by their ligands and the modulation of GPCR activation by small molecule drugs. (c) 2021 Elsevier B.V. All rights reserved.
PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY
(2022)
Article
Multidisciplinary Sciences
Marwa Amer, Oneda Leka, Piotr Jasko, Daniel Frey, Xiaodan Li, Richard A. Kammerer
Summary: The study aims to create a new GPCR tool that provides receptor stability and additional soluble surface for crystallization. The researchers selected the two-stranded antiparallel coiled coil as a domain fold and used it to replace the intracellular loop 3 of the β3 adrenergic receptor. They demonstrated that this approach is generally suitable for stabilizing GPCRs and has the potential to be used for structure elucidation.
SCIENTIFIC REPORTS
(2023)
Review
Pharmacology & Pharmacy
Sara Marsango, Graeme Milligan
Summary: GPR84 is a little-studied receptor that belongs to the rhodopsin-like class A G protein-coupled receptors, but it has attracted attention for its therapeutic potential. Its expression is up-regulated in response to acute inflammation and in inflammatory diseases, and activation of the receptor is involved in regulating pro-inflammatory responses and cell migration of the innate immune system. While GPR84 primarily signals through G(alpha i/o)-proteins, there is evidence that it can also recruit arrestin proteins upon agonist activation, which affects receptor internalization and desensitization. However, the phosphorylation patterns of GPR84 and their role in these processes are not well understood.
BRITISH JOURNAL OF PHARMACOLOGY
(2023)
Review
Pharmacology & Pharmacy
Yao Lu, Cassandra J. Hatzipantelis, Christopher J. Langmead, Gregory D. Stewart
Summary: Schizophrenia treatment currently relies on outdated science, and targeting dopamine receptors has limited efficacy and side effects. Non-dopaminergic GPCR-targeting drugs show promise but have not yet been successfully developed for clinical use. Recent attention has focused on non-dopaminergic GPCR-targeting drugs, which have demonstrated efficacy in certain symptoms of schizophrenia.
BRITISH JOURNAL OF PHARMACOLOGY
(2023)
Article
Chemistry, Applied
Hui-Wen Gu, Hui-Hui Zhou, Yi Lv, Qiao Wu, Yuan Pan, Zhi-Xin Peng, Xiao-Hua Zhang, Xiao-Li Yin
Summary: This study evaluates the feasibility of UV-Vis spectroscopy for the classification of Chinese red wine samples according to their geographical origins. The results show that UV-Vis spectroscopy combined with principal component analysis, orthogonal partial least squares-discriminant analysis, and support vector machine can accurately discriminate red wine samples from different origins. The study demonstrates that UV-Vis spectroscopy combined with machine learning-based modeling can be a simple, fast, and low-cost tool for routine identification of geographical origins of Chinese red wines.
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
(2023)
Article
Spectroscopy
Hanna S. Abbo, Chin Hung Lai, Salam J. J. Titinchi
Summary: The electronic spectra of chalcone derivatives were measured in ethanol and cyclohexane. Three band systems were identified, including local excitation of PhCH and PhCO rings and a charge transfer band associated with the CO-CH=CH moiety. The solvent affects the absorption spectra and causes the charge transfer band to consist of two electronic transitions. The study also investigated the effect of substituents on the phenyl rings of the chalcone derivatives.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2023)
Article
Cell Biology
Jeanette M. Einspahr, Douglas G. Tilley
Summary: Adhesion GPCRs, as the second-largest family of GPCRs, have not yet been targeted for clinical treatment despite increasing evidence of their physiological and pathological functions. They are associated with a variety of diseases, including cancer, central nervous system disorders, immunity, and inflammation.
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
(2022)
Article
Instruments & Instrumentation
Tu Phuong Pham Le, Pakorn Opaprakasit
Summary: This study utilized two-dimensional correlation UV-Vis spectroscopy to investigate the conversion mechanisms among TEMPO, TEMPO+, and TEMPOH, revealing that the conversion between TEMPO and TEMPOH in acidic solution is reversible but becomes irreversible over time. The addition of sodium hypochlorite can accelerate the conversion of TEMPO to TEMPO+.
APPLIED SPECTROSCOPY
(2021)
Review
Pharmacology & Pharmacy
Sergi Ferre, Francisco Ciruela, Carmen W. Dessauer, Javier Gonzalez-Maeso, Terence E. Hebert, Ralf Jockers, Diomedes E. Logothetis, Leonardo Pardo
Summary: The study proposes the concept of GPCR-effect assemblies (GEMMAs), which are pre-assembled before receptor activation and allow more efficient interactions between specific signaling components. This offers an alternative model to the conventional collision coupling model and explains the differential properties of GPCRs in different cellular environments.
PHARMACOLOGY & THERAPEUTICS
(2022)
Article
Instruments & Instrumentation
Jacek Sikorski, Norbert Obarski, Maciej Trzaskowski, Magdalena Matczuk
Summary: A simple methodology based on UV-visible spectroscopy was proposed and utilized for the initial characterization of changes in selectivity of doped magnetic nanoparticles. The doping processes of nanoparticles were confirmed using optical emission spectrometry, while the interaction between Cu-doped Fe3O4 nanoparticles and cuprizone was also confirmed. The results suggest the potential of UV-visible spectroscopy for the rapid qualification of magnetic nanoparticles in terms of separating chosen analytes from sample matrices.
APPLIED SPECTROSCOPY
(2021)
Article
Environmental Sciences
Sayed Mukit Hossain, Heeju Park, Hui-Ju Kang, Jong Seok Mun, Leonard Tijing, Inkyu Rhee, Jong-Ho Kim, Young-Si Jun, Ho Kyong Shon
Summary: Anatase TiO2/g-CN photocatalytic composites prepared by calcination showed efficient removal of atmospheric NO, with narrowed energy bandgaps observed in the composites. The generation of NO2 decreased under both UV and visible light irradiation as the calcination temperature increased during the synthesis of the catalysts.
Article
Chemistry, Multidisciplinary
Udeep Chawla, Suchithranga M. D. C. Perera, Steven D. E. Fried, Anna R. Eitel, Blake Mertz, Nipuna Weerasinghe, Michael C. Pitman, Andrey V. Struts, Michael F. Brown
Summary: Visual rhodopsin absorbs light and takes in approximately 80 water molecules to form a solvent-swollen active state, which is essential for activating the photoreceptor and is supported by molecular dynamics simulations. Force-based measurements show that the expansion of rhodopsin occurs through changes in cavity volumes and increased hydration in the active Meta II state. Furthermore, the binding and release of the C-terminal helix of transducin is coupled to hydration changes, potentially influencing visual signal amplification through a dynamic allosteric mechanism involving lipid and water interactions in the catalytic G-protein cycle.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Analytical
Ismail Tarhan
Summary: A new method for quantifying squalene in amaranth seed oil was proposed using spectroscopic techniques and partial least square calibration models. The best calibration model was obtained from FTIR spectroscopy with normal spectra, showing low RMSEC and high R-square values. The study demonstrated that FTIR spectroscopy coupled with PLS regression is an effective and environmentally friendly way to quantify squalene in ASO samples.
MICROCHEMICAL JOURNAL
(2021)
Article
Neurosciences
I-Shan Chen, Jodene Eldstrom, David Fedida, Yoshihiro Kubo
Summary: G-protein-gated inwardly rectifying K+ (GIRK; Kir3.x) channels play important roles in controlling cell excitation in various organs. Disease-associated mutations in these channels can lead to loss of K+ selectivity, with the G156S mutation showing a unique ion permeation pathway compared to other mutants.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Editorial Material
Neurosciences
Yoshihiro Kubo
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Physiology
Niklas Brake, Adamo S. Mancino, Yuhao Yan, Takushi Shimomura, Yoshihiro Kubo, Anmar Khadra, Derek Bowie
Summary: By combining electrophysiology and kinetic modeling, Brake et al. found that closed-state inactivation plays a significant role in the gating behavior of cardiac, skeletal muscle, and neuronal voltage-gated sodium channels. The study showed that both VSD-III and VSD-IV are necessary for the inactivation of the cardiac sodium channel, Nav1.5, and that all VSDs can modulate steady-state inactivation. The researchers also demonstrated that channel activation is partially determined by the movement of VSD-IV.
JOURNAL OF GENERAL PHYSIOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Andrey Rozenberg, Igor Kaczmarczyk, Donna Matzov, Johannes Vierock, Takashi Nagata, Masahiro Sugiura, Kota Katayama, Yuma Kawasaki, Masae Konno, Yujiro Nagasaka, Mako Aoyama, Ishita Das, Efrat Pahima, Jonathan Church, Suliman Adam, Veniamin A. Borin, Ariel Chazan, Sandra Augustin, Jonas Wietek, Julien Dine, Yoav Peleg, Akira Kawanabe, Yuichiro Fujiwara, Ofer Yizhar, Mordechai Sheves, Igor Schapiro, Yuji Furutani, Hideki Kandori, Keiichi Inoue, Peter Hegemann, Oded Beja, Moran Shalev-Benami
Summary: This study reports a new subfamily of microbial rhodopsins called bestrhodopsins, which are fused with bestrophin channels. Cryo-EM analysis reveals that bestrhodopsins form pentameric megacomplexes and undergo photoconversion. Bestrhodopsins behave as light-modulated anion channels.
NATURE STRUCTURAL & MOLECULAR BIOLOGY
(2022)
Article
Chemistry, Physical
Masahiro Sugiura, Kazuki Ishikawa, Kota Katayama, Yuji Sumii, Rei Abe-Yoshizumi, Satoshi P. Tsunoda, Yuji Furutani, Norio Shibata, Leonid S. Brown, Hideki Kandori
Summary: This study reports a novel photochemical reaction mediated by a microbial rhodopsin, leading to the selective transition from the all-trans to 7-cis form.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Masanori Hashimoto, Koichi Miyagawa, Manish Singh, Kota Katayama, Mitsuo Shoji, Yuji Furutani, Yasuteru Shigeta, Hideki Kandori
Summary: Heliorhodopsins (HeRs), a recently discovered family of rhodopsins, have an inverted membrane topology compared to other rhodopsins. ATR-FTIR spectroscopy studies have demonstrated the binding of Zn2+ to HeR, specifically affecting the structure and function. The specific binding site of Zn2+ was found to be located at the cytoplasmic side of TaHeR.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Takushi Shimomura, Kiichi Hirazawa, Yoshihiro Kubo
Summary: This study reveals that different conformations of DII-S4 determine the gating modes in Two-pore channels (TPCs), with the intermediate state representing the PIP2-gating mode. TPC3 is primarily voltage-dependent, while TPC2 is PIP2-gated and nonvoltage-dependent. Furthermore, the antidepressant desipramine induces voltage dependence in TPC2, and the flavonoid naringenin biases the mode preference from PIP2-gating to desipramine-induced voltage gating.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Biochemistry & Molecular Biology
Shoha Ochiai, Yuki Ichikawa, Sahoko Tomida, Yuji Furutani
Summary: Microbial rhodopsins are light-receptive proteins with various functions triggered by the photoisomerization of the retinal chromophore. The covalent bond linking the lysine residue and the protein backbone is not necessary for microbial rhodopsin function. However, a covalent bond at Lys-255 is important for the stable binding of the retinal chromophore and formation of an O intermediate to achieve light-driven Na+ pump function in KR2.
Editorial Material
Neurosciences
Yoshihiro Kubo, Peter Kohl
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Multidisciplinary Sciences
Shogo Hori, Michihiro Tateyama, Tsuyoshi Shirai, Yoshihiro Kubo, Osamu Saitoh
Summary: The authors discovered that the heat activation threshold of TRPV1 in tailed amphibians is reduced by substitution of two specific amino acids in the N-terminal region, suggesting their role in cool-habitat selection.
NATURE COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Kunisato Kuroi, Takashi Tsukamoto, Naoya Honda, Yuki Sudo, Yuji Furutani
Summary: This study investigated the primary proton transfer reactions of thermophilic rhodopsin and found that it is closely related to the structural change of the protein and optimized at high temperatures, which is not observed in other related proteins.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2023)
Article
Biochemistry & Molecular Biology
Sahoko Tomida, Akimori Wada, Yuji Furutani
Summary: Water is essential for protein function, particularly in ion transportation and color regulation. The dehydration of a sodium-pumping rhodopsin caused a color change, suggesting the importance of water molecules. Specifically, the hydrogen-bonding network and deprotonation state of certain amino acid residues were found to be maintained by water molecules in the protein KR2.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2023)
Article
Multidisciplinary Sciences
Yue Zhao, Shota Kusama, Yuji Furutani, Wei-Hong Huang, Chih-Wei Luo, Takao Fuji
Summary: The authors present a fast mid-infrared hyperspectral imaging technique using chirped pulse upconversion of sub-cycle pulses. The imaging technique offers adjustable field of view, large spectral range, and a lateral resolution of 15 μm. They demonstrated effective identification and mapping of different components in various samples. This technique has great potential and can be applied in chemical analysis, biology, and medicine.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Masahiro Sugiura, Kazuki Ishikawa, Kota Katayama, Yuji Sumii, Rei Abe-Yoshizumi, Satoshi P. Tsunoda, Yuji Furutani, Norio Shibata, Leonid S. Brown, Hideki Kandori
Summary: This study reports on a novel photochemistry mediated by a microbial rhodopsin, which selectively transforms the all-trans form to the 7-cis form. The reaction occurs in the dark with the all-trans form, but isomerizes into the 7-cis form upon illumination, accompanied by changes in protein structure and protonation.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)