{"title":"Allostery.","authors":"Mateu Montserrat-Canals, Gabriele Cordara, Ute Krengel","doi":"10.1017/S0033583524000209","DOIUrl":"https://doi.org/10.1017/S0033583524000209","url":null,"abstract":"<p><p><i>Allostery</i> describes the ability of biological macromolecules to transmit signals spatially through the molecule from an <i>allosteric</i> site – a site that is distinct from <i>orthosteric</i> binding sites of primary, endogenous ligands – to the functional or active site. This review starts with a historical overview and a description of the classical example of allostery – hemoglobin – and other well-known examples (aspartate transcarbamoylase, Lac repressor, kinases, G-protein-coupled receptors, adenosine triphosphate synthase, and chaperonin). We then discuss fringe examples of allostery, including intrinsically disordered proteins and inter-enzyme allostery, and the influence of dynamics, entropy, and conformational ensembles and landscapes on allosteric mechanisms, to capture the essence of the field. Thereafter, we give an overview over central methods for investigating molecular mechanisms, covering experimental techniques as well as simulations and artificial intelligence (AI)-based methods. We conclude with a review of allostery-based drug discovery, with its challenges and opportunities: with the recent advent of AI-based methods, allosteric compounds are set to revolutionize drug discovery and medical treatments.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"58 ","pages":"e5"},"PeriodicalIF":7.2,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143029367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reyhaneh Shakibi, Fatemeh Yazdipour, Hamed Abadijoo, Navid Manoochehri, Farshid Rostami Pouria, Taraneh Bajooli, Hossein Simaee, Parviz Abdolmaleki, Ali Khatibi, Mohammad Abdolahad, Ali Akbar Moosavi-Movahedi, Mohammad Ali Khayamian
{"title":"From Resting Potential to Dynamics: Advances in membrane Voltage Indicators and Imaging Techniques.","authors":"Reyhaneh Shakibi, Fatemeh Yazdipour, Hamed Abadijoo, Navid Manoochehri, Farshid Rostami Pouria, Taraneh Bajooli, Hossein Simaee, Parviz Abdolmaleki, Ali Khatibi, Mohammad Abdolahad, Ali Akbar Moosavi-Movahedi, Mohammad Ali Khayamian","doi":"10.1017/S0033583524000210","DOIUrl":"https://doi.org/10.1017/S0033583524000210","url":null,"abstract":"","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":" ","pages":"1-109"},"PeriodicalIF":7.2,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143009961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michał A Michałowski, Karol Kłopotowski, Grzegorz Wiera, Marta M Czyżewska, Jerzy W Mozrzymas
{"title":"Molecular mechanisms of the GABA type A receptor function.","authors":"Michał A Michałowski, Karol Kłopotowski, Grzegorz Wiera, Marta M Czyżewska, Jerzy W Mozrzymas","doi":"10.1017/S0033583524000179","DOIUrl":"https://doi.org/10.1017/S0033583524000179","url":null,"abstract":"<p><p>The GABA type A receptor (GABA<sub>A</sub>R) belongs to the family of pentameric ligand-gated ion channels and plays a key role in inhibition in adult mammalian brains. Dysfunction of this macromolecule may lead to epilepsy, anxiety disorders, autism, depression, and schizophrenia. GABA<sub>A</sub>R is also a target for multiple physiologically and clinically relevant modulators, such as benzodiazepines (BDZs), general anesthetics, and neurosteroids. The first GABA<sub>A</sub>R structure appeared in 2014, but the past years have brought a particularly abundant surge in structural data for these receptors with various ligands and modulators. Although the open conformation remains elusive, this novel information has pushed the structure-function studies to an unprecedented level. Electrophysiology, mutagenesis, photolabeling, and in silico simulations, guided by novel structural information, shed new light on the molecular mechanisms of receptor functioning. The main goal of this review is to present the current knowledge of GABA<sub>A</sub>R functional and structural properties. The review begins with an outline of the functional and structural studies of GABA<sub>A</sub>R, accompanied by some methodological considerations, especially biophysical methods, enabling the reader to follow how major breakthroughs in characterizing GABA<sub>A</sub>R features have been achieved. The main section provides a comprehensive analysis of the functional significance of specific structural elements in GABA<sub>A</sub>Rs. We additionally summarize the current knowledge on the binding sites for major GABA<sub>A</sub>R modulators, referring to the molecular underpinnings of their action. The final chapter of the review moves beyond examining GABA<sub>A</sub>R as an isolated macromolecule and describes the interactions of the receptor with other proteins in a broader context of inhibitory plasticity. In the final section, we propose a general conclusion that agonist binding to the orthosteric binding sites appears to rely on local interactions, whereas conformational transitions of bound macromolecule (gating) and allosteric modulation seem to reflect more global phenomena involving vast portions of the macromolecule.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"58 ","pages":"e3"},"PeriodicalIF":7.2,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142979875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Viroporins: discovery, methods of study, and mechanisms of host-membrane permeabilization.","authors":"Antonio Alcaraz, José L Nieva","doi":"10.1017/S0033583524000192","DOIUrl":"https://doi.org/10.1017/S0033583524000192","url":null,"abstract":"<p><p>The 'Viroporin' family comprises a number of mostly small-sized, integral membrane proteins encoded by animal and plant viruses. Despite their sequence and structural diversity, viroporins share a common functional trend: their capacity to assemble transmembrane channels during the replication cycle of the virus. Their selectivity spectrum ranges from low-pH-activated, unidirectional proton transporters, to size-limited permeating pores allowing passive diffusion of metabolites. Through mechanisms not fully understood, expression of viroporins facilitates virion assembly/release from infected cells, and subverts the cell physiology, contributing to cytopathogenicity. Compounds that interact with viroporins and interfere with their membrane-permeabilizing activity <i>in vitro</i>, are known to inhibit virus production. Moreover, viroporin-defective viruses comprise a source of live attenuated vaccines that prevent infection by notorious human and livestock pathogens. This review dives into the origin and evolution of the viroporin concept, summarizes some of the methodologies used to characterize the structure-function relationships of these important virulence factors, and attempts to classify them on biophysical grounds attending to their mechanisms of ion/solute transport across membranes.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"58 ","pages":"e1"},"PeriodicalIF":7.2,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142979888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structural biology inside multicellular specimens using electron cryotomography.","authors":"Ido Caspy, Zhexin Wang, Tanmay A M Bharat","doi":"10.1017/S0033583525000010","DOIUrl":"10.1017/S0033583525000010","url":null,"abstract":"","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":" ","pages":"1-39"},"PeriodicalIF":7.2,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7617309/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142972090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Piero Andrea Temussi, Stephen R Martin, Annalisa Pastore
{"title":"Life and death of Yfh1: how cool is cold denaturation.","authors":"Piero Andrea Temussi, Stephen R Martin, Annalisa Pastore","doi":"10.1017/S0033583524000180","DOIUrl":"https://doi.org/10.1017/S0033583524000180","url":null,"abstract":"<p><p>Yeast frataxin (Yfh1) is a small natural protein from yeast that has the unusual property of undergoing cold denaturation at temperatures above the freezing point of water when under conditions of low ionic strength. This peculiarity, together with remarkable resilience, allows the determination, for the whole protein as well as for individual residues, of the stability curve, that is the temperature dependence of the free energy difference between the unfolded and folded forms. The ease of measuring stability curves without the need to add denaturants or introduce <i>ad hoc</i> destabilizing mutations makes this protein an ideal 'tool' for investigating the influence of many environmental factors on protein stability. The present review aims at recapitulating all the open questions that Yfh1 has helped to address, including understanding the differences and commonalities of the cold, heat and pressure unfolded states. This protein thus offers a unique tool for studying aspects of protein stability so far been considered difficult to assess and provides important guidelines that could allow the identification of other similar systems.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"58 ","pages":"e2"},"PeriodicalIF":7.2,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142972051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Single-molecule orientation-localization microscopy: Applications and approaches.","authors":"Oumeng Zhang, Matthew D Lew","doi":"10.1017/S0033583524000167","DOIUrl":"10.1017/S0033583524000167","url":null,"abstract":"<p><p>Single-molecule orientation-localization microscopy (SMOLM) builds upon super-resolved localization microscopy by imaging orientations and rotational dynamics of individual molecules in addition to their positions. This added dimensionality provides unparalleled insights into nanoscale biophysical and biochemical processes, including the organization of actin networks, movement of molecular motors, conformations of DNA strands, growth and remodeling of amyloid aggregates, and composition changes within lipid membranes. In this review, we discuss recent innovations in SMOLM and cover three key aspects: (1) biophysical insights enabled by labeling strategies that endow fluorescent probes to bind to targets with orientation specificity; (2) advanced imaging techniques that leverage the physics of light-matter interactions and estimation theory to encode orientation information with high fidelity into microscope images; and (3) computational methods that ensure accurate and precise data analysis and interpretation, even in the presence of severe shot noise. Additionally, we compare labeling approaches, imaging hardware, and publicly available analysis software to aid the community in choosing the best SMOLM implementation for their specific biophysical application. Finally, we highlight future directions for SMOLM, such as the development of probes with improved photostability and specificity, the design of “smart” adaptive hardware, and the use of advanced computational approaches to handle large, complex datasets. This review underscores the significant current and potential impact of SMOLM in deepening our understanding of molecular dynamics, paving the way for future breakthroughs in the fields of biophysics, biochemistry, and materials science.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"57 ","pages":"e17"},"PeriodicalIF":7.2,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142877763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mark A B Kreutzberger, Ravi R Sonani, Edward H Egelman
{"title":"Cryo-EM reconstruction of helical polymers: Beyond the simple cases.","authors":"Mark A B Kreutzberger, Ravi R Sonani, Edward H Egelman","doi":"10.1017/S0033583524000155","DOIUrl":"10.1017/S0033583524000155","url":null,"abstract":"<p><p>Helices are one of the most frequently encountered symmetries in biological assemblies. Helical symmetry has been exploited in electron microscopic studies as a limited number of filament images, in principle, can provide all the information needed to do a three-dimensional reconstruction of a polymer. Over the past 25 years, three-dimensional reconstructions of helical polymers from cryo-EM images have shifted completely from Fourier-Bessel methods to single-particle approaches. The single-particle approaches have allowed people to surmount the problem that very few biological polymers are crystalline in order, and despite the flexibility and heterogeneity present in most of these polymers, reaching a resolution where accurate atomic models can be built has now become the standard. While determining the correct helical symmetry may be very simple for something like F-actin, for many other polymers, particularly those formed from small peptides, it can be much more challenging. This review discusses why symmetry determination can be problematic, and why trial-and-error methods are still the best approach. Studies of many macromolecular assemblies, such as icosahedral capsids, have usually found that not imposing symmetry leads to a great reduction in resolution while at the same time revealing possibly interesting asymmetric features. We show that for certain helical assemblies asymmetric reconstructions can sometimes lead to greatly improved resolution. Further, in the case of supercoiled flagellar filaments from bacteria and archaea, we show that the imposition of helical symmetry can not only be wrong, but is not necessary, and obscures the mechanisms whereby these filaments supercoil.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"57 ","pages":"e16"},"PeriodicalIF":7.2,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11730170/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Graph theory approaches for molecular dynamics simulations.","authors":"Amun C Patel, Souvik Sinha, Giulia Palermo","doi":"10.1017/S0033583524000143","DOIUrl":"10.1017/S0033583524000143","url":null,"abstract":"<p><p>Graph theory, a branch of mathematics that focuses on the study of graphs (networks of nodes and edges), provides a robust framework for analysing the structural and functional properties of biomolecules. By leveraging molecular dynamics (MD) simulations, atoms or groups of atoms can be represented as nodes, while their dynamic interactions are depicted as edges. This network-based approach facilitates the characterization of properties such as connectivity, centrality, and modularity, which are essential for understanding the behaviour of molecular systems. This review details the application and development of graph theory-based models in studying biomolecular systems. We introduce key concepts in graph theory and demonstrate their practical applications, illustrating how innovative graph theory approaches can be employed to design biomolecular systems with enhanced functionality. Specifically, we explore the integration of graph theoretical methods with MD simulations to gain deeper insights into complex biological phenomena, such as allosteric regulation, conformational dynamics, and catalytic functions. Ultimately, graph theory has proven to be a powerful tool in the field of molecular dynamics, offering valuable insights into the structural properties, dynamics, and interactions of molecular systems. This review establishes a foundation for using graph theory in molecular design and engineering, highlighting its potential to transform the field and drive advancements in the understanding and manipulation of biomolecular systems.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"57 ","pages":"e15"},"PeriodicalIF":7.2,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Atomic molecular dynamics simulation advances of <i>de novo</i>-designed proteins.","authors":"Moye Wang, Anqi Ma, Hongjiang Wang, Xiaotong Lou","doi":"10.1017/S0033583524000131","DOIUrl":"10.1017/S0033583524000131","url":null,"abstract":"<p><p>Proteins are vital biological macromolecules that execute biological functions and form the core of synthetic biological systems. The history of <i>de novo</i> protein has evolved from initial successes in subordinate structural design to more intricate protein creation, challenging the complexities of natural proteins. Recent strides in protein design have leveraged computational methods to craft proteins for functions beyond their natural capabilities. Molecular dynamics (MD) simulations have emerged as a crucial tool for comprehending the structural and dynamic properties of <i>de novo</i>-designed proteins. In this study, we examined the pivotal role of MD simulations in elucidating the sampling methods, force field, water models, stability, and dynamics of <i>de novo-</i>designed proteins, highlighting their potential applications in diverse fields. The synergy between computational modeling and experimental validation continued to play a crucial role in the creation of novel proteins tailored for specific functions and applications.</p>","PeriodicalId":20828,"journal":{"name":"Quarterly Reviews of Biophysics","volume":"57 ","pages":"e14"},"PeriodicalIF":7.2,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142787031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}