Biophysical reviews最新文献

{"title":"The Na⁺,K⁺-ATPase and its stoichiometric ratio: some thermodynamic speculations.","authors":"R Daniel Peluffo, Julio A Hernández","doi":"10.1007/s12551-023-01082-5","DOIUrl":"10.1007/s12551-023-01082-5","url":null,"abstract":"<p><p> Almost seventy years after its discovery, the sodium-potassium adenosine triphosphatase (the sodium pump) located in the cell plasma membrane remains a source of novel mechanistic and physiologic findings. A noteworthy feature of this enzyme/transporter is its robust stoichiometric ratio under physiological conditions: it sequentially counter-transports three sodium ions and two potassium ions against their electrochemical potential gradients per each hydrolyzed ATP molecule. Here we summarize some present knowledge about the sodium pump and its physiological roles, and speculate whether energetic constraints may have played a role in the evolutionary selection of its characteristic stoichiometric ratio.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"539-552"},"PeriodicalIF":4.9,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480117/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10560245","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}

{"title":"Diabetes-induced electrophysiological alterations on neurosomes in ganglia of peripheral nervous system.","authors":"José Henrique Leal-Cardoso, Francisco Walber Ferreira-da-Silva, Andrelina Noronha Coelho-de-Souza, Kerly Shamyra da Silva-Alves","doi":"10.1007/s12551-023-01094-1","DOIUrl":"10.1007/s12551-023-01094-1","url":null,"abstract":"<p><p>Diabetes mellitus (DM) leads to medical complications, the epidemiologically most important of which is diabetic peripheral neuropathy (DPN). Electrophysiology is a major component of neural functioning and several studies have been undertaken to elucidate the neural electrophysiological alterations caused by DM and their mechanisms of action. Due to the importance of electrophysiology for neuronal function, the review of the studies dealing predominantly with electrophysiological parameters and mechanisms in the neuronal somata of peripheral neural ganglia of diabetic animals during the last 45 years is here undertaken. These studies, using predominantly techniques of electrophysiology, most frequently patch clamp for voltage clamp studies of transmembrane currents through ionic channels, have investigated the experimental DPN. They also have demonstrated that various cellular and molecular mechanisms of action of diabetic physiopathology at the level of biophysical electrical parameters are affected in DPN. Thus, they have demonstrated that several passive and active transmembrane voltage parameters, related to neuronal excitability and neuronal functions, are altered in diabetes. The majority of the studies agreed that DM produces depolarization of the resting membrane potential; alters excitability, increasing and decreasing it in dorsal root ganglia (DRG) and in nodose ganglion, respectively. They have tried to relate these changes to sensorial alterations of DPN. Concerning ionic currents, predominantly studied in DRG, the most frequent finding was increases in Na⁺, Ca²⁺, and TRPV1 cation current, and decreases in K⁺ current. This review concluded that additional studies are needed before an understanding of the hierarchized, time-dependent, and integrated picture of the contribution of neural electrophysiological alterations to the DPN could be reached. DM-induced electrophysiological neuronal alterations that so far have been demonstrated, most of them likely important, are either consistent with the DPN symptomatology or suggest important directions for improvement of the elucidation of DPN physiopathology, which the continuation seems to us very relevant.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"625-638"},"PeriodicalIF":4.9,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480376/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10180612","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}

{"title":"Mechanosensitive aquaporins.","authors":"Marcelo Ozu, Luciano Galizia, Juan José Alvear-Arias, Miguel Fernández, Agustín Caviglia, Rosario Zimmermann, Florencia Guastaferri, Nicolás Espinoza-Muñoz, Moira Sutka, Lorena Sigaut, Lía Isabel Pietrasanta, Carlos González, Gabriela Amodeo, José Antonio Garate","doi":"10.1007/s12551-023-01098-x","DOIUrl":"10.1007/s12551-023-01098-x","url":null,"abstract":"<p><p>Cellular systems must deal with mechanical forces to satisfy their physiological functions. In this context, proteins with mechanosensitive properties play a crucial role in sensing and responding to environmental changes. The discovery of aquaporins (AQPs) marked a significant breakthrough in the study of water transport. Their transport capacity and regulation features make them key players in cellular processes. To date, few AQPs have been reported to be mechanosensitive. Like mechanosensitive ion channels, AQPs respond to tension changes in the same range. However, unlike ion channels, the aquaporin's transport rate decreases as tension increases, and the molecular features of the mechanism are unknown. Nevertheless, some clues from mechanosensitive ion channels shed light on the AQP-membrane interaction. The GxxxG motif may play a critical role in the water permeation process associated with structural features in AQPs. Consequently, a possible gating mechanism triggered by membrane tension changes would involve a conformational change in the cytoplasmic extreme of the single file region of the water pathway, where glycine and histidine residues from loop B play a key role. In view of their transport capacity and their involvement in relevant processes related to mechanical forces, mechanosensitive AQPs are a fundamental piece of the puzzle for understanding cellular responses.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"497-513"},"PeriodicalIF":4.9,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480384/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10189652","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}

{"title":"Protein folding rate evolution upon mutations.","authors":"Jorge A Vila","doi":"10.1007/s12551-023-01088-z","DOIUrl":"10.1007/s12551-023-01088-z","url":null,"abstract":"<p><p>Despite the spectacular success of cutting-edge protein fold prediction methods, many critical questions remain unanswered, including why proteins can reach their native state in a biologically reasonable time. A satisfactory answer to this simple question could shed light on the slowest folding rate of proteins as well as how mutations-amino-acid substitutions and/or post-translational modifications-might affect it. Preliminary results indicate that (i) Anfinsen's dogma validity ensures that proteins reach their native state on a reasonable timescale regardless of their sequence or length, and (ii) it is feasible to determine the evolution of protein folding rates without accounting for epistasis effects or the mutational trajectories between the starting and target sequences. These results have direct implications for evolutionary biology because they lay the groundwork for a better understanding of why, and to what extent, mutations-a crucial element of evolution and a factor influencing it-affect protein evolvability. Furthermore, they may spur significant progress in our efforts to solve crucial structural biology problems, such as how a sequence encodes its folding.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"661-669"},"PeriodicalIF":4.9,"publicationDate":"2023-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480377/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10191064","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}

{"title":"Exploring the structural acrobatics of fold-switching proteins using simplified structure-based models.","authors":"Ignacio Retamal-Farfán, Jorge González-Higueras, Pablo Galaz-Davison, Maira Rivera, César A Ramírez-Sarmiento","doi":"10.1007/s12551-023-01087-0","DOIUrl":"10.1007/s12551-023-01087-0","url":null,"abstract":"<p><p>Metamorphic proteins are a paradigm of the protein folding process, by encoding two or more native states, highly dissimilar in terms of their secondary, tertiary, and even quaternary structure, on a single amino acid sequence. Moreover, these proteins structurally interconvert between these native states in a reversible manner at biologically relevant timescales as a result of different environmental cues. The large-scale rearrangements experienced by these proteins, and their sometimes high mass interacting partners that trigger their metamorphosis, makes the computational and experimental study of their structural interconversion challenging. Here, we present our efforts in studying the refolding landscapes of two quintessential metamorphic proteins, RfaH and KaiB, using simplified dual-basin structure-based models (SBMs), rigorously footed on the energy landscape theory of protein folding and the principle of minimal frustration. By using coarse-grained models in which the native contacts and bonded interactions extracted from the available experimental structures of the two native states of RfaH and KaiB are merged into a single Hamiltonian, dual-basin SBM models can be generated and savvily calibrated to explore their fold-switch in a reversible manner in molecular dynamics simulations. We also describe how some of the insights offered by these simulations have driven the design of experiments and the validation of the conformational ensembles and refolding routes observed using this simple and computationally efficient models.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"787-799"},"PeriodicalIF":4.9,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480104/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10245712","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}

{"title":"The diverse family of Cys-loop receptors in <i>Caenorhabditis elegans</i>: insights from electrophysiological studies.","authors":"Guillermina Hernando, Ornella Turani, Noelia Rodriguez Araujo, Cecilia Bouzat","doi":"10.1007/s12551-023-01080-7","DOIUrl":"10.1007/s12551-023-01080-7","url":null,"abstract":"<p><p>Cys-loop receptors integrate a large family of pentameric ligand-gated ion channels that mediate fast ionotropic responses in vertebrates and invertebrates. Their vital role in converting neurotransmitter recognition into an electrical impulse makes these receptors essential for a great variety of physiological processes. In vertebrates, the Cys-loop receptor family includes the cation-selective channels, nicotinic acetylcholine and 5-hydroxytryptamine type 3 receptors, and the anion-selective channels, GABA_A and glycine receptors, whereas in invertebrates, the repertoire is significantly larger. The free-living nematode <i>Caenorhabditis elegans</i> has the largest known Cys-loop receptor family as well as unique receptors that are absent in vertebrates and constitute attractive targets for anthelmintic drugs. Given the large number and variety of Cys-loop receptor subunits and the multiple possible ways of subunit assembly, <i>C. elegans</i> offers a large diversity of receptors although only a limited number of them have been characterized to date. <i>C. elegans</i> has emerged as a powerful model for the study of the nervous system and human diseases as well as a model for antiparasitic drug discovery. This nematode has also shown promise in the pharmaceutical industry search for new therapeutic compounds. <i>C. elegans</i> is therefore a powerful model organism to explore the biology and pharmacology of Cys-loop receptors and their potential as targets for novel therapeutic interventions. In this review, we provide a comprehensive overview of what is known about the function of <i>C. elegans</i> Cys-loop receptors from an electrophysiological perspective.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"733-750"},"PeriodicalIF":4.9,"publicationDate":"2023-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480131/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10191062","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}

{"title":"Photo-induced protein modifications: a range of biological consequences and applications.","authors":"Claudia Cecilia Vera, Claudio Darío Borsarelli","doi":"10.1007/s12551-023-01081-6","DOIUrl":"10.1007/s12551-023-01081-6","url":null,"abstract":"<p><p>Proteins are the most abundant biomolecules in living organisms and tissues and are also present in many natural and processed foods and beverages, as well as in pharmaceuticals and therapeutics. When exposed to UV-visible light, proteins containing endogenous or exogenous chromophores can undergo direct and indirect photochemical processes, resulting in protein modifications including oxidation of residues, cross-linking, proteolysis, covalent binding to molecules and interfaces, and conformational changes. When these modifications occur in an uncontrolled manner in a physiological context, they can lead to biological dysfunctions that ultimately result in cell death. However, rational design strategies involving light-activated protein modification have proven to be a valuable tool for the modulation of protein function or even for the construction of new biomaterials. This mini-review describes the fundamentals of photochemical processes in proteins and explores some of their emerging biomedical and nanobiotechnological applications, such as photodynamic therapy (PDT), photobonding for wound healing, photobioprinting, photoimmobilization of biosensors and enzymes for sensing, and biocatalysis, among others.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"569-576"},"PeriodicalIF":4.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480124/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10245711","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}

{"title":"A view from the President of the Indian Biophysical Society.","authors":"Madan Rao","doi":"10.1007/s12551-023-01072-7","DOIUrl":"10.1007/s12551-023-01072-7","url":null,"abstract":"<p><p>This Commentary introduces the readers of Biophysical Reviews to the current president of the Indian Biophysical Society and details a few recent activities of the society in its domestic and international promotion of the biophysics as a scientific discipline.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 3","pages":"305-306"},"PeriodicalIF":4.9,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10310661/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9735997","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}

{"title":"Label-free fluorescence microscopy: revisiting the opportunities with autofluorescent molecules and harmonic generations as biosensors and biomarkers for quantitative biology.","authors":"María José García, Andrés Kamaid, Leonel Malacrida","doi":"10.1007/s12551-023-01083-4","DOIUrl":"10.1007/s12551-023-01083-4","url":null,"abstract":"<p><p>Over the past decade, the utilization of advanced fluorescence microscopy technologies has presented numerous opportunities to study or re-investigate autofluorescent molecules and harmonic generation signals as molecular biomarkers and biosensors for in vivo cell and tissue studies. The label-free approaches benefit from the endogenous fluorescent molecules within the cell and take advantage of their spectroscopy properties to address biological questions. Harmonic generation can be used as a tool to identify the occurrence of fibrillar or lipid deposits in tissues, by using second and third-harmonic generation microscopy. Combining autofluorescence with novel techniques and tools such as fluorescence lifetime imaging microscopy (FLIM) and hyperspectral imaging (HSI) with model-free analysis of phasor plots has revolutionized the understanding of molecular processes such as cellular metabolism. These tools provide quantitative information that is often hidden under classical intensity-based microscopy. In this short review, we aim to illustrate how some of these technologies and techniques may enable investigation without the need to add a foreign fluorescence molecule that can modify or affect the results. We address some of the most important autofluorescence molecules and their spectroscopic properties to illustrate the potential of these combined tools. We discuss using them as biomarkers and biosensors and, under the lens of this new technology, identify some of the challenges and potentials for future advances in the field.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 4","pages":"709-719"},"PeriodicalIF":4.9,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10480099/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10189654","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}

{"title":"Should young athletes be screened for cardiomyopathies to reduce the burden of sudden cardiac death in athletes?","authors":"Grace McColgan, Mauricio Villarroel, Katja Gehmlich","doi":"10.1007/s12551-023-01085-2","DOIUrl":"10.1007/s12551-023-01085-2","url":null,"abstract":"<p><p>In this correspondence, we highlight the risk of sudden cardiac death associated with undiagnosed cardiomyopathies. Life-threatening arrhythmias, which underlie sudden cardiac death, can be triggered by high-intensity exercise. It raises the question whether, and if so, how athletes should be screened for cardiomyopathies. The example of practice from Italy is discussed. We also briefly discuss novel developments, such as wearable biosensors and machine learning, which could be applied to screening for cardiomyopathies in future.</p>","PeriodicalId":9094,"journal":{"name":"Biophysical reviews","volume":"15 3","pages":"321-327"},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10310562/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9742909","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}