Article
Multidisciplinary Sciences
Johann Biedermann, Sebastian Braunbeck, Andrew J. R. Plested, Han Sun
Summary: Fast excitatory synaptic transmission in the central nervous system relies on the AMPA-type glutamate receptor (AMPAR), which incorporates a nonselective cation channel. Recent studies combining molecular dynamic simulations and electrophysiology have revealed the ion permeation mechanisms of AMPA receptors, showing that Na+, K+, and Cs+ can permeate at physiological rates through a simple selectivity filter structure. The permissive architecture of the filter allows for rapid, nonselective cation permeation and copermeation by water, with Cs+ slightly more permeant than Na+ due to preferential binding sites.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
C. Kevin Song, V. Andrew Molina, Ruofan Chen, A. Isabelle Gagnon, Young Hoon Koh, Benoit Roux, R. Tobin Sosnick
Summary: The dynamics and folding of potassium channel pore domain monomers are intertwined with tetramer assembly kinetics. Monomers can adopt nonnative conformations but can be locked into a native-like conformation through engineered disulfide bonds. Folding occurs via fast and slow routes within the protein-dense region, with constructs bearing disulfide bonds favoring the faster pathway. Despite its tetrameric nature, the folding process is concentration independent, with the rate-limiting step occurring after monomer association in the protein-dense region.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Biochemistry & Molecular Biology
Angelo Felline, Simone Conti, Michele Seeber, Marco Cecchini, Francesca Fanelli
Summary: This article presents the second update of Wordom, a program for manipulation and analysis of conformational ensembles from molecular simulations. The update expands existing modules and adds 21 new modules, which can be grouped into three sets analyzing atomic fluctuations and communication, ion-channel dynamics, and structural deformation. The updates enhance Wordom's suitability, completeness, user-friendliness, and efficiency for biomolecular simulation analysis.
COMPUTATIONAL AND STRUCTURAL BIOTECHNOLOGY JOURNAL
(2023)
Article
Engineering, Chemical
Chunyan Liu, Qi Xin, Cai Qin, Maorui Jiang, Glenn V. Lo, Yusheng Dou, Shuai Yuan
Summary: In this study, a dark-state model of GtACR1 was built and isomerized through molecular dynamics simulation, providing insights into the molecular mechanism of light-gated anion conduction. It was found that the all-trans to 13-cis photoisomerization of the retinal chromophore does not open the channel but results in a pre-opened K-like intermediate. Proton transfer between E68 and D234 was identified as the key step for chloride-ion conducting. A revised channel opening pathway model of GtACR1 was proposed based on the analysis of (de)protonation of E68 and D234.
Article
Biochemistry & Molecular Biology
Qi Xin, Wenying Zhang, Shuai Yuan
Summary: In this study, the intermediate structures of ChR2 in the photocycle were modeled and molecular dynamics simulations were performed to understand the mechanism of ion channel opening. The results show that the structural models of the intermediates are reasonable and the ion channel is open in the P520 state.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Food Science & Technology
Lorenzo Pallante, Marta Malavolta, Gianvito Grasso, Aigli Korfiati, Seferina Mavroudi, Bojan Mavkov, Athanasios Kalogeras, Christos Alexakos, Vanessa Martos, Daria Amoroso, Giacomo di Benedetto, Dario Piga, Konstantinos Theofilatos, Marco A. Deriu
Summary: This review provides an overview of the molecular mechanisms involved in taste transduction, focusing on taste receptors and the activation/deactivation of specific cell signalling pathways. It also highlights the advances in molecular research and computational investigation of ligand-receptor interaction related to taste receptors, aiming to understand the transfer of taste information.
TRENDS IN FOOD SCIENCE & TECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Jie Liu, Tao Zhang, Shuyu Sun
Summary: The ion transport in protein nanochannels during peritoneal dialysis was investigated using molecular dynamics (MD) simulations and the MD Monte Carlo (MDMC) algorithm. The spatial distribution of ions and their temporal properties were accurately predicted, validating the suitability of the MDMC method for handling ion transport problems in protein nanochannels.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
Sergio Perez-Conesa, Eric G. Keeler, Dongyu Zhang, Lucie Delemotte, Ann E. McDermott
Summary: The pH-gated prokaryotic channel KcsA has been extensively studied as the first potassium channel with an x-ray structure determined, but questions related to the allosteric coupling between its gates remain open. Solid-state nuclear magnetic resonance (SSNMR) can provide insights into the molecular basis of activation mechanisms by studying the wild-type protein under activating conditions, and simulation techniques such as molecular dynamics (MD) simulations can help determine the activated state captured in SSNMR experiments.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Delin Sun, Stewart He, W. F. Drew Bennett, Camille L. Bilodeau, Olaf S. Andersen, Felice C. Lightstone, Helgi I. Ingolfsson
Summary: Research on gramicidin A (gA) subunit dimerization in lipid bilayers revealed a dimer structure with two subunits connected by six hydrogen bonds, as well as two additional dimer structures stabilized by four or two hydrogen bonds. The temporal evolution study found that the dimer can form directly with six hydrogen bonds, or through paths involving two or four hydrogen bonds.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Biochemistry & Molecular Biology
Xiaoqian Zhang, Hua Yu, Xiangdong Liu, Chen Song
Summary: The L210F Orai mutant has a more hydrated hydrophobic region and wider hydrophobic gate compared to the wild-type, and key conformational changes in the rotation of F210 and F171 may facilitate the opening of two gates, potentially activating the Orai channel independent of STIM.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2021)
Article
Materials Science, Multidisciplinary
N. Girotto, L. Linhart, F. Libisch
Summary: Stacking two layers of slightly twisted two-dimensional materials alters the physical properties of the resulting bilayer, including electronic and phononic band structures. Our findings suggest that manipulating phononic and electronic properties through suitable twisting structures provides an opportunity to investigate the contributions of electron-phonon interactions to the observed correlated states.
Article
Engineering, Chemical
Keita Yano, Masayuki Iwamoto, Takaaki Koshiji, Shigetoshi Oiki
Summary: This study establishes an accurate method for evaluating the osmotic permeability of lipid bilayers under constant tension, and known unstirred layers. This method helps to better understand the water flux process across cell membranes by quantifying membrane tension and unstirred layers.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Crystallography
Yuliya Kordonskaya, Vladimir Timofeev, Yulia A. Dyakova, Margarita A. Marchenkova, Yury Pisarevsky, Mikhail Kovalchuk
Summary: The study demonstrates that the dimer model considering all precipitant ions in the structure has the most accurate free energy values, while in the absence of precipitant ions in the solution, the monomeric form is more energetically favorable.
Review
Pharmacology & Pharmacy
Varun Dewaker, Ashish R. Sharma, Utsab Debnath, Sung Taek Park, Hyeong Su Kim
Summary: This review provides an update on molecular dynamics simulation studies of the TRPV1 channel, focusing on its gating mechanism, ligand-binding sites, and implications for drug design. The article also explores challenges in developing modulators, SAR optimization, and clinical trial studies.
DRUG DISCOVERY TODAY
(2023)
Article
Biochemistry & Molecular Biology
Christopher Faulkner, Nora H. de Leeuw
Summary: Fentanyl, a potent opioid analgesic, is used in combination with propofol in general anesthesia. Molecular dynamics simulations revealed that fentanyl acts as a stabilizer, helping propofol to remain in binding sites. This study provides insights into the interactions between different drugs in the anesthesia process.
JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS
(2022)
Article
Chemistry, Organic
Ramona Birke, Julia Ast, Dorien A. Roosen, Joon Lee, Kilian Rossmann, Christiane Huhn, Bettina Mathes, Michael Lisurek, David Bushiri, Han Sun, Ben Jones, Martin Lehmann, Joshua Levitz, Volker Haucke, David J. Hodson, Johannes Broichhagen
Summary: This study reports a method to make dyes impermeable for surface protein analysis. By synthesizing dyes with charged sulfonate groups and combining them with red and far-red dyes, Sulfo549 and Sulfo646 are obtained. These dyes are further linked to benzylguanine and choloralkane substrates for rapid cell fixation and protein labeling. The dyes have desirable photophysical properties and can differentiate proteins labeled in extracellular and intracellular compartments through co-labeling with permeable rhodamine. Additionally, these dyes can be used for transfection of neurons and imaging with super-resolution microscopy. This work provides a new approach for developing dyes with cellular impermeability and has important implications for accurate protein analysis with intracellular labeling.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Plant Sciences
Xiao-Lu Li, Tong Ru, Armando Navarro-Vazquez, Peter Lindemann, Marc Nazare, Xu-Wen Li, Yue-Wei Guo, Han Sun
Summary: This study successfully elucidated the structures of two uncommon marine gorgonian-derived symmetric dimers using various anisotropic and computational NMR methods. Additionally, it revealed the relative configuration of these dimers.
JOURNAL OF NATURAL PRODUCTS
(2022)
Article
Biology
Yuchen Hao, Estelle Toulme, Benjamin Koenig, Christian Rosenmund, Andrew J. R. Plested
Summary: Optical report of neurotransmitter release allows visualization of excitatory synaptic transmission. However, without targeting to synapses, the specificity of the fluorescent signal is uncertain. To address this, the reporter iGluSnFR was fused to glutamate receptor auxiliary proteins to target it to postsynaptic sites. This improved the properties of iGluSnFR and demonstrated the importance of subcellular targeting for optogenetic actuators and reporters.
Article
Chemistry, Medicinal
Florian Karl Schackert, Johann Biedermann, Saeid Abdolvand, Sonja Minniberger, Chen Song, Andrew J. R. Plested, Paolo Carloni, Han Sun
Summary: This study investigates calcium conduction in calcium-permeable AMPAR using Molecular Dynamics (MD) simulations and multiscale Quantum Mechanics/Molecular Mechanics (QM/MM) simulations. The results explain the distinct calcium permeability in different RNA-edited forms of GluA2 and provide unprecedented insights into Ca(2+) permeation mechanisms in AMPARs.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Neurosciences
Steffen Fricke, Magnus Harnau, Florian Hetsch, Haoran Liu, Julia Leonhard, Anna Eylmann, Pina Knauff, Han Sun, Marcus Semtner, Jochen C. Meier
Summary: High concentrations of cesium can have adverse effects on neuronal physiology, prompting the FDA to issue a warning. It has been found that cesium activates glycine receptors, and further investigation revealed the binding profiles of cesium and potassium to these receptors through experiments and simulations.
FRONTIERS IN MOLECULAR NEUROSCIENCE
(2023)
Review
Pharmacology & Pharmacy
Christian Dahlstroem, Themistoklis Paraschiakos, Han Sun, Sabine Windhorst
Summary: Cellular actin dynamics is regulated by various actin binding proteins (ABPs), including nucleating, bundling, cross-linking, capping, and severing proteins. This review focuses on the regulation of actin dynamics by ABPs, with a specific emphasis on the role of cofilin-1, an F-actin severing protein, and L-plastin, an F-actin bundling protein. As the up-regulation of these proteins in cancer is associated with malignant progression, the cryo-EM structure of F-actin with the respective ABP could be used as a template for in silico drug design to disrupt their interaction.
BIOCHEMICAL PHARMACOLOGY
(2023)
Editorial Material
Physiology
Nathaniel Smith, Han Sun
Summary: A computational study suggests that pi-bulges are crucial for the gating mechanisms of Cav channels, regulating the binding of enantiomeric DHP.
JOURNAL OF GENERAL PHYSIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Iva Lucic, Pin-Lian Jiang, Andreas Franz, Yuval Bursztyn, Fan Liu, Andrew J. R. Plested
Summary: Using unnatural amino acid mutagenesis, a mutant of CaMKII was created that can form a covalent linkage to Calmodulin upon UV light illumination. The binding of Calmodulin to this mutant does not perturb the oligomeric state of CaMKII, and it can be activated by UV-induced binding of Calmodulin in the absence of calcium. This mutant shows potential for controlling CaMKII activity with light.
Article
Biology
Iva Lucic, Leonie Heluin, Pin-Lian Jiang, Alejandro G. Castro Scalise, Cong Wang, Andreas Franz, Florian Heyd, Markus C. Wahl, Fan Liu, Andrew J. R. Plested
Summary: The dodecameric protein kinase CaMKII is expressed throughout the body and plays a crucial role in synaptic plasticity and memory. Contrary to previous expectations, our study reveals that subunit exchange is not the main mechanism for the spread of CaMKII activity. Instead, inter-holoenzyme phosphorylation (IHP) is identified as the mechanism for spreading phosphorylation.
Article
Multidisciplinary Sciences
Claudia Bohg, Carl Oster, Berke Turkaydin, Michael Lisurek, Pascal Sanchez-Carranza, Sascha Lange, Tillmann Utesch, Han Sun, Adam Lange
Summary: Rhomboid proteases hydrolyze substrate helices within the lipid bilayer to release soluble domains from the membrane. The lateral gate formed by TM2 and TM5 in the model rhomboid GlpG allows access of the hydrophobic substrate to the active site. The opening dynamics of the lateral gate in rhomboid proteases strongly affects their enzymatic activity.
Article
Chemistry, Medicinal
Maria Isabel Fernandez-Bachiller, Songhwan Hwang, Maria Elena Schembri, Peter Lindemann, Monica Guberman, Svenja Herziger, Edgar Specker, Hans Matter, David W. Will, Jorg Czech, Michael Wagner, Armin Bauer, Herman Schreuder, Kurt Ritter, Matthias Urmann, Volkmar Wehner, Han Sun, Marc Nazare
Summary: The study examined two series of factor Xa ligands through experimental and computational approaches, identifying new ligands with higher affinity and demonstrating the terminal alkyne moiety as a suitable non-classical bioisosteric replacement for higher halogen-pi aryl interactions.
JOURNAL OF MEDICINAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Yuexiao Lin, Jiaqian Li, Si-Yong Qin, Han Sun, Yan-Ling Yang, Armando Navarro-Vazquez, Xinxiang Lei
Summary: NMR spectroscopy in anisotropic media is a powerful technique for determining the structure of organic molecules. However, obtaining multiple independent and non-linearly related sets of NMR data from the same organic solvent system remains a challenge. In this study, a programmable strategy was introduced to construct distinct peptide-based alignment media, enabling the measurement of independent sets of RDCs in an efficient and accurate manner.
Article
Biochemistry & Molecular Biology
Ankita Chadda, Alexander G. Kozlov, Binh Nguyen, Timothy M. Lohman, Eric A. Galburt
Summary: In this study, it was found that the DNA damage response in Mycobacterium tuberculosis differs from well-studied model bacteria. The DNA repair helicase UvrD1 in Mtb is activated through a redox-dependent process and is closely associated with the homo-dimeric Ku protein. Additionally, Ku protein is shown to stimulate the helicase activity of UvrD1.
JOURNAL OF MOLECULAR BIOLOGY
(2024)