Journal of General Physiology最新文献_第3页

On the mechanism of hypomagnesemia with treatment-resistant seizures caused by variants of the Na+,K+-ATPase α1 subunit (ATP1A1). Na+，K+- atp酶α1亚基（ATP1A1）变异引起的低镁血症伴治疗抵抗性癫痫发作的机制

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-06-30 DOI: 10.1085/jgp.202513959

Nicolas Colmano, Daniel Self, Hang N Nielsen, Rikke Holm, Chai C Gopalasingam, Ryota Fujimura, Kazuhiro Abe, Bente Vilsen, Sho T Yano, Pablo Artigas

{"title":"On the mechanism of hypomagnesemia with treatment-resistant seizures caused by variants of the Na+,K+-ATPase α1 subunit (ATP1A1).","authors":"Nicolas Colmano, Daniel Self, Hang N Nielsen, Rikke Holm, Chai C Gopalasingam, Ryota Fujimura, Kazuhiro Abe, Bente Vilsen, Sho T Yano, Pablo Artigas","doi":"10.1085/jgp.202513959","DOIUrl":"10.1085/jgp.202513959","url":null,"abstract":"Various dominant disease phenotypes are caused by germline variants of ATP1A1, the gene for the ubiquitously expressed Na+,K+-ATPase (NKA) α1 subunit. What characteristics link specific variants to a particular disease phenotype remains unclear. We used heterologous expression in mammalian cells and Xenopus oocytes to evaluate the characteristics of α1 variants causing hypomagnesemia with treatment-resistant seizures: L302R, G303R, M859R, and W931R. Cell survival in the presence of micromolar ouabain was reduced in cells expressing ouabain-resistant versions of these variants, indicating defective function of the variants relative to WT. Fluorescently tagged WT-α1 expressed in HEK293 cells showed plasmalemma localization, while all variants displayed increased cytosolic signal. In variant-expressing oocytes under voltage clamp, each variant showed passive \"leak\" currents, which were unaffected by ouabain in L302R and M859R, partially inhibited by ouabain in G303R and enhanced by ouabain in W931R. Na+ and Cl‒ permeate through G303R and W931R. M859R and W931R presented small K+-activated ouabain-inhibitable NKA currents that were absent in L302R and G303R. Growth of cells in ouabain and enzymatic studies demonstrated Na+/K+-dependent active transport for W931R, albeit with reduced Na+ affinity. We solved the cryo-EM structure of W931R-α1β1 with bound ouabain at 3 Å resolution. The structure showed a distorted transmembrane segment M9, which causes a concavity in the detergent micelle, suggesting that similar distortions may provide a leak pathway at the protein-lipid interface. Our results demonstrate that besides a loss of NKA function, all four variants carry an aberrant leak current that probably underlies the seizures and the hypomagnesemia characterizing this phenotype.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13317510/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148354698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Conformational changes upon pore blocker removal reveal conductive states of TMEM16A. 去除孔阻滞剂后的构象变化揭示了TMEM16A的导电状态。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-07-02 DOI: 10.1085/jgp.202513961

Christina A Stephens, Frank V Marcoline, Christian J Peters, Michael Grabe

{"title":"Conformational changes upon pore blocker removal reveal conductive states of TMEM16A.","authors":"Christina A Stephens, Frank V Marcoline, Christian J Peters, Michael Grabe","doi":"10.1085/jgp.202513961","DOIUrl":"10.1085/jgp.202513961","url":null,"abstract":"TMEM16A is a Ca2+-activated anion channel that provides direct electrical feedback to the plasma membrane in response to intracellular Ca2+. Its conductive state remains unresolved, leaving questions about gating, Cl- permeation, and modulation by Ca2+, depolarization, and lipids. To investigate the open state, we performed molecular dynamics simulations of TMEM16A bound to the putative open-state blocker 1PBC. After inhibitor removal, the putative, pore-lining helix TM4 developed kinks at two sites: an upper site that opens the pore for Cl- permeation and a deeper site causing constriction. A conserved hydrophobic network between TM3 and TM4 persisted in most open structures but separated during extreme dilation, allowing lipids to transiently block the pore. Patch-clamp recordings indicated that the intact network promotes activation. Further simulations yielded >60 Cl- permeation events and a single-channel conductance that matched experiment. Additional electrostatic and kinetic modeling indicated that TMEM16A's transition from outward-rectification to ohmic conductance with increasing Ca2+ results from a weak voltage dependence of binding of Ca2+ ions, which acts cooperatively to open the pore.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148370871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Allosteric interactions between RyR channels justify intracellular Ca2+ release of skeletal muscle in quantitative detail. RyR通道之间的变构相互作用证明了骨骼肌细胞内Ca2+释放的定量细节。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-07-21 DOI: 10.1085/jgp.202613968

Eduardo Rios, Gonzalo Pizarro

{"title":"Allosteric interactions between RyR channels justify intracellular Ca2+ release of skeletal muscle in quantitative detail.","authors":"Eduardo Rios, Gonzalo Pizarro","doi":"10.1085/jgp.202613968","DOIUrl":"10.1085/jgp.202613968","url":null,"abstract":"This modeling study explains the intracellular Ca2+ release that controls contraction of skeletal muscles of mammals as emerging from a statistical ensemble of couplons. Couplons are constituted by identical sarcoplasmic reticulum RyR1 channels, arranged in native \"checkerboard\" double-row pattern, with alternate channels (the V class) in physical contact with CaV1.1 tetrads resident in the electrically excitable T-tubular membrane. Activation starts from these and propagates allosterically to the RyRs devoid of CaV contacts (the C class). Both activations are imposed by changes in free energy of channel states, derived from electrical work on the CaV mobile charges. The allosteric connections, resulting in reciprocal energy changes, are interlaced, so that the couplon becomes a highly reactive continuum where allosteric effects may propagate from end to end. A robust inactivation of C channels maintains this highly excitable device under graded voltage control. The model reproduces within the variance of experimental observations the cell level records of Ca2+ flux, including voltage dependence and kinetics, under multiple combinations of voltage clamp pulses, and accounts for the conditioning effects known as \"quantal release\" and \"deterministic inactivation.\" The simulations, which describe individual channel evolutions as stochastic Markov chains, are also consistent with the Ca2+ events recorded at the subcellular microdomain level as well as observations of coupled gating in bilayers. No explicit Ca2+ roles on activation or inactivation are required. The good model-vs.-experiment match enables inferences on mechanisms, their specializations in muscle tissues, and their variations in different taxa. It also encourages modular incorporation into more comprehensive models of cellular function.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13387315/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148551157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Model prokaryotic potassium channels: Predictive power and relevance to eukaryotic channels. 模型原核钾通道：预测能力和真核通道的相关性。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-07-09 DOI: 10.1085/jgp.202614025

Philipp A M Schmidpeter, Crina M Nimigean

{"title":"Model prokaryotic potassium channels: Predictive power and relevance to eukaryotic channels.","authors":"Philipp A M Schmidpeter, Crina M Nimigean","doi":"10.1085/jgp.202614025","DOIUrl":"10.1085/jgp.202614025","url":null,"abstract":"Prokaryotic ion channels have played a foundational role in defining the structural and mechanistic principles of potassium channel function. Beyond their historical importance, we argue that bacterial channels retain, even today, predictive power for understanding the regulation of complex eukaryotic channels. Their reduced architectural complexity, high expression yields, and compatibility with controlled functional and structural assays enable direct correlations between conformational states and activity that remain difficult to achieve for many eukaryotic channels. While numerous prokaryotic ion channels across different families have advanced our understanding of membrane protein structure and function, we focus here on a subset of bacterial potassium channels-KcsA, MthK, and SthK-as experimentally tractable model systems. Using these examples, we illustrate how prokaryotic models have anticipated conserved mechanisms of permeation, selectivity, bundle crossing and filter gating, ball-and-chain inactivation, and lipid modulation-often years before these processes could be structurally or functionally resolved in eukaryotic homologs. Importantly, insights from prokaryotic channels not only recapitulate known behaviors but also guide hypothesis generation, experimental design, and mechanistic interpretation for eukaryotic systems under otherwise inaccessible conditions. As high-resolution cryo-EM increasingly reveals conformations of complex channels, the ability to test underlying relationships between structure and function becomes paramount. We propose that prokaryotic ion channels serve as valuable predictive biophysical platforms that can bridge atomic-level mechanisms and physiological regulation, continuing to impact how ion channel function is conceptualized and experimentally interrogated.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148413865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Differential Na+ chelation underlies opposite effects of aconitine and bulleyaconitine on sodium channel permeation. 不同的钠离子螯合作用是乌头碱和乌头碱对钠离子通道渗透的相反作用的基础。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-08-06 DOI: 10.1085/jgp.202614023

Boris S Zhorov

{"title":"Differential Na+ chelation underlies opposite effects of aconitine and bulleyaconitine on sodium channel permeation.","authors":"Boris S Zhorov","doi":"10.1085/jgp.202614023","DOIUrl":"https://doi.org/10.1085/jgp.202614023","url":null,"abstract":"Voltage-gated sodium (Nav) channel site-2 diterpenoid alkaloids, including potent toxin aconitine (ACO), are generally considered gating modifiers that stabilize activated/open conformations and impair fast inactivation. In contrast, the structurally related compound bulleyaconitine (BACO), which is used clinically in China, produces antagonist-like suppression of Na+ current. Compared with BACO, ACO has two additional hydroxyl groups and lacks a 4-methoxy substituent at aromatic ring. Atomic mechanisms underlying the opposite effects of BACO and ACO are unknown. In cryoEM structure 7w77, a BACO-related alkaloid (BACORA) binds in fenestration I/II of Nav1.3, exposing tertiary nitrogen toward the pore lumen. Here, BACO and ACO were docked into the channel. Monte Carlo energy minimizations (MCMs) yielded alkaloids' binding poses located akin, but not identical to that of BACORA. MCM profiles of a hydrated Na+ pulled through the pore in the presence of protonated alkaloids reveal electrostatic barriers that would block ion permeation. In contrast, in the presence of unprotonated ACO, hydrated Na+ was transiently chelated by nitrogen and two oxygen atoms and would pass by the toxin. In BACO, the absence of hydroxyl groups near nitrogen decreases the probability of Na+ chelation and would shift the equilibrium of H+/Na+ exchange at nitrogen toward the protonated state that would block ion conduction. These results suggest that stabilization of the open activation gate can be mechanistically decoupled from ion permeation when a ligand exposes protonated nitrogen to the pore lumen, creating a conduction barrier. The proposed mechanism of Na+ permeation through ACO-bound channel is analogous to that described for the Nav1.5 channel with batrachotoxin (BTX) in fenestration III/IV. Together, these findings explain the opposite effects of ACO and BACO on Nav channels and highlight analogous mechanisms of Nav activation by ACO and BTX despite their binding in opposite fenestrations.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148681211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinetic reconstruction of graded membrane excitability in Paramecium. 草履虫膜梯度兴奋性的动力学重建。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-07-07 DOI: 10.1085/jgp.202613977

Takashi Tominaga, Yoko Tominaga

{"title":"Kinetic reconstruction of graded membrane excitability in Paramecium.","authors":"Takashi Tominaga, Yoko Tominaga","doi":"10.1085/jgp.202613977","DOIUrl":"10.1085/jgp.202613977","url":null,"abstract":"Electrical excitability in the ciliate Paramecium links sensory transduction to behavioral output through voltage-dependent control of ciliary activity. Despite its long history as a model organism, a quantitative framework that can reconstruct graded membrane excitability from overlapping macroscopic current components has remained incomplete. Here, we developed a conductance-based kinetic model for Paramecium multimicronucleatum using controlled voltage-clamp protocols and Hodgkin-Huxley-type analyses. We first characterized the resting leak component and two major late components: a depolarization-activated component (Idepo) and a hyperpolarization-activated component (Ihyper). Together, these components produced a conductance minimum near the resting potential. Using this baseline framework, we operationally isolated the transient inward Ca2+ current (ICa). Ca2+-dependent inactivation was strongly non-single exponential and was described by a phenomenological parameterization relating channel availability to cumulative Ca2+ entry during conditioning. Recovery from inactivation was substantially slower than the onset of inactivation. Finally, we integrated these parameterized components into a single-membrane equation and reconstructed the graded membrane responses observed in current-clamp recordings. The model reproduced the initial depolarizing peak and the subsequent sustained depolarized phase followed by repolarization. Together, these results demonstrate that an integrated kinetic description can capture major features of graded membrane excitability in P. multimicronucleatum under the present recording conditions.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148399940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electrophysiology in nanoscale compartments. 纳米级隔间的电生理学。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-07-20 DOI: 10.1085/jgp.202614011

Madeleine R Howell, Rosalind J Xu, Adam E Cohen

{"title":"Electrophysiology in nanoscale compartments.","authors":"Madeleine R Howell, Rosalind J Xu, Adam E Cohen","doi":"10.1085/jgp.202614011","DOIUrl":"https://doi.org/10.1085/jgp.202614011","url":null,"abstract":"Voltage-gated ion channels play important roles in many membrane-enclosed structures, including synaptic vesicles, endosomes, mitochondria, chloroplasts, viruses, and bacteria. Here, we study how compartment size and channel gating interact to shape voltage dynamics and ion content in sub-micron structures. In small compartments, assumptions underlying conductance-based (Hodgkin-Huxley type) models of membrane voltage must be relaxed: (1) stochastic gating of individual ion channels can quickly and substantially change membrane voltage; (2) these changes can equilibrate faster than channel state dwell times; and (3) ionic currents, even though as few as two channels, can substantially alter ionic concentrations. We adapted conductance-based models to incorporate these effects, and we then simulated voltage dynamics of small vesicles as a function of vesicle radius and channel density. We identified regimes in this parameter space with qualitatively distinct dynamics. We then performed stochastic simulations to explore the role of NaV1.5 in the maturation of macrophage endosomes. The stochastic model predicted dramatically different dynamics compared with a deterministic approach. Electrophysiology of nanoscale structures can be very different from larger structures, even when ion channel composition and density are preserved.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148521537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Giving structure meaning: Modelling the cellular synapse of excitation-contraction coupling in skeletal muscle. 赋予结构意义：模拟骨骼肌兴奋-收缩耦合的细胞突触。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-07-30 DOI: 10.1085/jgp.202614061

Werner Melzer

引用次数: 0

Differential regulation of β1-dependent voltage shifts and kinetic modulation by an extracellular glutamate in NaV1.6 VSDIV. 细胞外谷氨酸对NaV1.6 VSDIV中β1依赖性电压转移的差异调节和动力学调节。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-06-29 DOI: 10.1085/jgp.202614018

Maxime Lammens, Jolien De Waele, Alain J Labro, Filip Van Petegem, Frank Bosmans

{"title":"Differential regulation of β1-dependent voltage shifts and kinetic modulation by an extracellular glutamate in NaV1.6 VSDIV.","authors":"Maxime Lammens, Jolien De Waele, Alain J Labro, Filip Van Petegem, Frank Bosmans","doi":"10.1085/jgp.202614018","DOIUrl":"https://doi.org/10.1085/jgp.202614018","url":null,"abstract":"Auxiliary β1 subunits play an important role in modulating voltage-gated Na+ (NaV) channel gating, thereby influencing their voltage-dependent behavior and overall function. Here, we examine β1 modulation of human NaV1.6 channels expressed in Xenopus laevis oocytes and identify a glutamate in the extracellular S3-S4 loop of domain IV (VSDIV; E1607) as a key determinant of β1-induced voltage shifts. Co-expression of β1 produces hyperpolarizing shifts in activation and steady-state inactivation (SSI) and accelerates macroscopic inactivation kinetics. Substitution of E1607 with lysine or alanine, but not the negatively charged aspartate, selectively attenuates β1-induced shifts in voltage dependence while preserving effects on slope factor, inactivation kinetics, and persistent current. Pharmacological perturbation of VSDIV with the α-scorpion toxin AaHII attenuates β1-dependent shifts in SSI without abolishing β1 effects on gating kinetics. Together, these findings identify an extracellular VSDIV element that contributes to β1-dependent control of voltage dependence and support a model in which β1 modulates NaV1.6 gating through VSDIV-linked transitions.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148347266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanistic insights into DCPIB inhibition of VRAC: Electrostatic control and binding plasticity. DCPIB抑制VRAC的机制：静电控制和结合可塑性。

IF 3.2 2区医学

Journal of General Physiology Pub Date : 2026-09-07 Epub Date: 2026-06-25 DOI: 10.1085/jgp.202513953

Héctor Gaitán-Peñas, Salomé Llabrés, Marina Pedrola, Marc González-Subías, Jordi Juárez-Jiménez, Michael Pusch, Rodolfo Lavilla, Raúl Estévez

{"title":"Mechanistic insights into DCPIB inhibition of VRAC: Electrostatic control and binding plasticity.","authors":"Héctor Gaitán-Peñas, Salomé Llabrés, Marina Pedrola, Marc González-Subías, Jordi Juárez-Jiménez, Michael Pusch, Rodolfo Lavilla, Raúl Estévez","doi":"10.1085/jgp.202513953","DOIUrl":"10.1085/jgp.202513953","url":null,"abstract":"The volume-regulated anion channel (VRAC), formed by LRRC8 heteromers, regulates cell volume and is a promising therapeutic target. DCPIB is the most widely used VRAC inhibitor, yet its binding mechanism remains poorly defined. Although structural studies suggested a role of residue R103 in LRRC8A in DCPIB binding, its functional relevance has been unclear. Here, we combined electrophysiology in Xenopus oocytes and LRRC8-/- HEK293T cells with MD simulations and rational design of DCPIB analogs. Mutations of R103 abolished ATP-dependent block of VRAC but did not affect inhibition by DCPIB or the related inhibitor carbenoxolone (CBX), indicating distinct binding mechanisms. Simulations revealed two DCPIB-binding modes: one involving R103 and another engaging K51 and hydrophobic residues. In R103F mutants, DCPIB retained binding via π-stacking and alternative electrostatic contacts, explaining its persistent inhibition. Attempts to disrupt these interactions by mutating K51 led to nonfunctional channels. To further probe the role of electrostatic groups in the binding of DCPIB to VRAC, we synthesized derivatives varying charge and hydrophobicity. Functional assays and steered MD showed that analogs retaining the carboxylate group maintain high-affinity binding, whereas esterified forms exhibit rapid unbinding and reduced potency. Biphenyl substitutions increased binding energy but imposed steric penalties, suggesting a trade-off between affinity and accessibility. Our findings reveal an adaptable binding mechanism for DCPIB, contrasting with described lipid-displacement mechanisms for other VRAC inhibitors, and establish electrostatic complementarity as the primary determinant of high-affinity block. These insights provide a framework for rational design of next-generation VRAC inhibitors with improved specificity.","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"158 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148334497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0