The Journal of Physical Chemistry B最新文献_第2页

FE65 Recognition Rewires the Dynamic Contact Network of the Amyloid Precursor Protein Intracellular Domain FE65识别重新连接淀粉样前体蛋白胞内结构域的动态接触网络

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-23 DOI: 10.1021/acs.jpcb.6c04695

Nabanita Mandal, Marie Skepö

{"title":"FE65 Recognition Rewires the Dynamic Contact Network of the Amyloid Precursor Protein Intracellular Domain","authors":"Nabanita Mandal, Marie Skepö","doi":"10.1021/acs.jpcb.6c04695","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c04695","url":null,"abstract":"The amyloid precursorprotein intracellular domain (AICD)is ashort, intrinsically disordered signaling fragment that mediates interactionswith adaptor proteins involved in APP trafficking and transcription-associatedregulation. Among these partners, FE65 recognizes the conserved YENPTY-containingregion of AICD, yet the ensemble-level mechanism underlying this interactionremains unclear. Here, we use molecular dynamics simulations to compareunbound and bound AICD together with YENPTY-motif mutant variants.In the unbound state, AICD samples a heterogeneous conformationalensemble dominated by disordered states while retaining transientlocal structure and recurrent intramolecular contacts. Upon FE65 binding,AICD does not collapse into a single rigid conformation; instead,its conformational ensemble is redistributed toward interaction-compatiblesubstates. Residue-resolved contact analyses identify localized interactionhotspots within and adjacent to the YENPTY region, including aromaticand polar residues that dominate the bound-state contact network.Mutations within the YENPTY motif alter the balance between compactand extended conformations while preserving the intrinsically disorderedcharacter of the peptide. Together, these results support a recognitionmechanism in which FE65 binds a partially organized AICD ensemblevia localized interaction hotspots and ensemble reweighting, ratherthan through complete disorder-to-order folding. This work providesa molecular framework for understanding APP intracellular-tail recognitionand its regulation by sequence-localized perturbations. More broadly,these findings illustrate how intrinsically disordered motifs canachieve specific molecular recognition through redistribution of dynamiccontact networks without undergoing complete disorder-to-order transitions.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11718–11731"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multicomponent Crystallization Via Bottom-Up Coarse-Grained Modeling: CO2 Hydrate Formation 通过自下而上的粗粒度建模的多组分结晶：二氧化碳水合物形成

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-22 DOI: 10.1021/acs.jpcb.6c05167

Liang-Yao Huang, Kuntal Ghosh, Shiang-Tai Lin, Gregory A. Voth

{"title":"Multicomponent Crystallization Via Bottom-Up Coarse-Grained Modeling: CO2 Hydrate Formation","authors":"Liang-Yao Huang, Kuntal Ghosh, Shiang-Tai Lin, Gregory A. Voth","doi":"10.1021/acs.jpcb.6c05167","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c05167","url":null,"abstract":"The formation of carbon dioxide (CO2) clathrate hydratesis critical for technologies ranging from carbon sequestration tocold energy applications. While all-atom simulations provide molecularinsight, their computational cost severely limits the study of hydratenucleation and growth. Coarse-grained (CG) models offer a compellingalternative for reaching the necessary time and length scales. Inthis work, we develop a novel CG model for the CO2-watersystem using a bottom-up approach. We utilize the BUMPer model, aneffective pairwise potential that implicitly captures water’smany-body effects, and systematically derive the remaining CO2–CO2 and water-CO2 interactions.Our central finding is that a single potential for the water-CO2 interaction cannot adequately describe both the disorderedaqueous solution and the structured solid hydrate. To overcome this,we introduce a state-dependent approach, deriving separate potentialsfrom prenucleation liquid and crystalline hydrate configurations.This composite potential, which is also pairwise, accurately capturesthe phase transition, successfully driving the formation of stablehydrate crystals and promoting the self-assembly of individual cages.This work establishes that complex multicomponent crystallizationcan be modeled using only two-body CG potentials, providing a robustand computationally efficient methodology for studying hydrate dynamics.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11887–11902"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assigning the Low-Energy Excitons in Far-Red Photosystem II through Atomistic Modeling 远红光系统II中低能激子的原子模型分配

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-21 DOI: 10.1021/acs.jpcb.6c05218

Samuele Giannini, Luca Ancillotti, Lorenzo Cupellini

{"title":"Assigning the Low-Energy Excitons in Far-Red Photosystem II through Atomistic Modeling","authors":"Samuele Giannini, Luca Ancillotti, Lorenzo Cupellini","doi":"10.1021/acs.jpcb.6c05218","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c05218","url":null,"abstract":"Far-red light photoacclimation of cyanobacteria extendsthe spectralrange of oxygenic photosynthesis through the incorporation of chlorophylls(Chls) d and f into natural photosystems,but the energetic organization of these pigments remains poorly understood.Here, we combine electronic-structure calculations with atomisticQM/MM and polarizable QM/MM approaches to determine the site energies,electronic couplings, and excitonic structure of the far-red PSIIfrom Synechococcus sp. PCC 7335. In particular, weuse benchmark calculations against spin-component-scaled CC2 to assessthe accuracy of long-range corrected density functionals for describingthe relative energetics of Chls a, d, and f. Our calculations reveal that the energetictuning of the far-red pigments is governed primarily by protein electrostatics,whereas structural distortions and environmental polarization makecomparatively minor contributions. We find significant excitonic interactionswithin the subset of CP47 chlorophylls, while the reaction-centerChl d remains largely localized. The resulting excitonicHamiltonian quantitatively reproduces both the far-red absorptionspectrum and the sequence of exciton energies extracted from two-dimensionalelectronic spectroscopy, enabling a first-principles assignment ofthe low-energy excitons to specific Chl f and Chl d pigments. These results provide an atomistic picture ofthe far-red excitonic landscape and establish a quantitative basisfor future simulations of excitation energy transfer and charge separationin far-red photosystems.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11746–11756"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Classical Density Functional Theory in Physical Chemistry 物理化学中的经典密度泛函理论

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 DOI: 10.1021/acs.jpcb.6c06726

Guillaume Jeanmairet, Barbara Kirchner, René van Roij

引用次数: 0

Molecular Insights into the Precipitation Suppression of Salts in Near-Critical Water: Dielectric Restructuring and Competitive Coordination in NaCl–Na2SO4 Mixtures 近临界水中盐抑制沉淀的分子研究：NaCl-Na2SO4混合物中的介电结构重组和竞争配位

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-23 DOI: 10.1021/acs.jpcb.6c03930

Zhe Li, Zhenmin Cheng

{"title":"Molecular Insights into the Precipitation Suppression of Salts in Near-Critical Water: Dielectric Restructuring and Competitive Coordination in NaCl–Na2SO4 Mixtures","authors":"Zhe Li, Zhenmin Cheng","doi":"10.1021/acs.jpcb.6c03930","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c03930","url":null,"abstract":"The complex aggregation and phase behaviors of inorganicsalts in near-critical aqueous environments remain a key challenge forhigh-temperature fluid technologies. In multicomponent brines wherehighly soluble and aggregation-prone salts coexist, competitive interactionsintroduce significant physical and chemical complexities. Using apolarizable force field to capture dynamic polarization and dielectricresponses under extreme conditions, this study investigates the microscopicion aggregation mechanisms in ternary NaCl–Na2SO4–H2O brines. By evaluating the structural,dynamical, and energetic evolution, we elucidate mechanisms governingthe suppression of agglomeration. Results indicate that introducinghighly soluble NaCl retains macroscopic solvent density via electrostriction.This profound electrostriction resists severe thermal expansion, preservinga resilient, liquid-like dielectric screening capacity. Acting insynergy with the competitive coordination and steric hindrance fromabundant chloride ions, this sustained dense fluid environment thermodynamicallyforces the precipitation-prone sulfate anions to remain in a solvatedand dispersed regime. This work provides a molecular-level understandingof anomalous solubility retention in mixed near-critical brines, offeringtheoretical insights for managing scaling in high-temperature aqueoussystems.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11852–11865"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hesperetin Inhibits Aβ Early Aggregation by Disrupting the Continuity of the β-Sheet Structure 橙皮素通过破坏β片结构的连续性来抑制Aβ的早期聚集

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-26 DOI: 10.1021/acs.jpcb.6c06062

Yu Zhang, Yelong Wu, Shengli Zhang, Lei Zhang, Xuhua Li

{"title":"Hesperetin Inhibits Aβ Early Aggregation by Disrupting the Continuity of the β-Sheet Structure","authors":"Yu Zhang, Yelong Wu, Shengli Zhang, Lei Zhang, Xuhua Li","doi":"10.1021/acs.jpcb.6c06062","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c06062","url":null,"abstract":"The misfolding and pathological aggregation of amyloid-β(Aβ) into insoluble amyloid deposits are closely associatedwith Alzheimer’s disease (AD). Inhibiting early Aβ assemblyis a critical strategy for the development of antiamyloid therapeutics.Hesperetin (HST), a natural flavanone abundant in citrus fruits, hasbeen reported to inhibit Aβ fibrillogenesis and reduce Aβ-associatedcytotoxicity. However, the molecular mechanism underlying HST-mediatedinhibition of Aβ aggregation remains unclear. In particular,whether HST acts through mechanisms similar to other natural compoundsor employs a distinct inhibitory strategy is yet to be determined.Here, we employed replica exchange molecular dynamics (REMD) simulationsto investigate how HST modulates Aβ early aggregation and β-sheetassembly at the atomic level. The results demonstrate that HST disruptsthe continuity of β-sheet structures within Aβ dimers,as evidenced by restricted β-strand extension. Mechanistically,HST preferentially interacts with aggregation-prone regions of Aβthrough a synergistic interaction network of hydrogen-bonding, hydrophobic,π–π stacking, and cation–π interactions.Notably, HST-mediated hydrogen bonding with the Aβ backboneperturbs the local hydrogen-bonding environment required for β-sheetextension, while cooperative nonpolar and aromatic interactions furtherstabilize HST-bound conformations and weaken intra- and intermolecularinteraction networks involved in Aβ self-assembly. Collectively,these findings reveal a specific mechanism by which HST regulatesAβ aggregation through disruption of β-sheet continuity,which provides atomic-level insights into the antiamyloid activityof natural flavanones.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11788–11798"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In Situ Study of Electron-Tunneling through Dynamic Interface at Individual Nanoemulsions by Multimodal Single-Entity Electrochemistry 利用多模态单实体电化学技术原位研究单个纳米乳剂动态界面上的电子隧穿

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-21 DOI: 10.1021/acs.jpcb.6c04932

Anuradha Khatri Chhetri, Mandip Adhikari, Jiyeon Kim

{"title":"In Situ Study of Electron-Tunneling through Dynamic Interface at Individual Nanoemulsions by Multimodal Single-Entity Electrochemistry","authors":"Anuradha Khatri Chhetri, Mandip Adhikari, Jiyeon Kim","doi":"10.1021/acs.jpcb.6c04932","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c04932","url":null,"abstract":"To overcome criticalchallenges in modern drug delivery, lipidnanocarriers such as nanoemulsions (NEs) have emerged as superiordrug carriers. While advancements in nanotechnology allow precisecontrol over NE size and structure, the rational design of their functionalityremains difficult. This is because functionality is primarily dominatedby dynamically or statically formed interfacial structures that cannotbe easily characterized using ex situ bulk analysisor electron microscopy. Herein, we demonstrate multimodal single-entityelectrochemistry (MSEE)─combining amperometric SEE with voltammetry─to in situ probe electron-tunneling through the dynamic interfacesof intact, individual NEs. Using highly monodisperse NEs synthesizedwith varying concentrations of Pluronic block copolymer surfactants,we investigated interfacial electron transfer (ET) rates at discreteNEs. Notably, ET through the NE interface aligns with the predictionsof the Marcus–Hush theory. We determined the effective interfacialthickness, tunneling-distance decay constant, ET rate constants, andtransfer coefficient. This enabled angstrom-resolution differentiationof interfacial structures and structure-dependent charge-transferbehaviors across a series of NEs, independent of morphological sizedifferences. Our MSEE approach provides a powerful electrochemicalframework for investigating nanostructure–function relationshipsin lipid nanocarriers with mixed interfacial layers, ultimately aidingin the optimization of desired functionality such as delivery efficiency,release kinetics, and carrier stability.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11931–11941"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unraveling Hierarchical Structure in Ionic Liquid–Extractant Mixtures with X-ray Scattering 用x射线散射揭示离子液体-萃取剂混合物的层次结构

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-26 DOI: 10.1021/acs.jpcb.6c04769

Xiaoyu Wang, Allison A. Peroutka, Soenke Seifert, Michael J. Servis

{"title":"Unraveling Hierarchical Structure in Ionic Liquid–Extractant Mixtures with X-ray Scattering","authors":"Xiaoyu Wang, Allison A. Peroutka, Soenke Seifert, Michael J. Servis","doi":"10.1021/acs.jpcb.6c04769","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c04769","url":null,"abstract":"Liquid–liquidextraction (LLE) is the predominantmethodfor the selective recovery and separation of many critical materials,including rare earth elements and platinum group metals. Ionic liquids(ILs) have been proposed to replace traditional solvents in LLE toenhance or manipulate separation performance. The tunable nanostructureof ILs is a unique and defining characteristic that impacts theirfunction, but how that structure is affected by mixing with the LLEextractant is not understood. To investigate this, we combine small-angleX-ray scattering (SAXS) and molecular dynamics (MD) simulations. SAXSprofiles computed from the MD simulations are in good agreement withthe experimental data. Known pure IL nanostructures persist upon theaddition of the malonamide extractant. Decomposition of the simulationstructure factors shows extractant distribution between the domainsof the IL solvent. In addition, these mixtures also show strong compositionfluctuations at low q, indicating inhomogeneity relatedto phase instability between IL and the extractant. In a trend exactlyopposite to that observed in conventional molecular alkane solvents,increasing the alkyl tail length in ILs depresses the fluctuations,suggesting that enhanced IL hydrophobicity promotes mixture stability.These findings suggest that traditional ligand design strategy is,in fact, counterproductive and needs to be reevaluated for LLE processesusing ILs. This study provides the basis for understanding the fundamentalsof IL–extractant mixtures and will lead to the rational designof both IL and the extractant for more efficient separation processes.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11866–11874"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of the Piezoelectric Response of Zwitterionic Liquids and Their Ionic Liquid Counterparts 两性离子液体及其同类离子液体压电响应的比较

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-24 DOI: 10.1021/acs.jpcb.6c05681

Andrew J. Wendel, Angira Roy, Sheryl S. Blanchard, Gary A. Baker, G. J. Blanchard

{"title":"Comparison of the Piezoelectric Response of Zwitterionic Liquids and Their Ionic Liquid Counterparts","authors":"Andrew J. Wendel, Angira Roy, Sheryl S. Blanchard, Gary A. Baker, G. J. Blanchard","doi":"10.1021/acs.jpcb.6c05681","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c05681","url":null,"abstract":"We have evaluated the direct piezoelectric response offour zwitterionicliquids (ZwILs): 4-(1-(2-(2-methoxyethoxy)ethyl)-1H-imidazol-3-ium-3-yl)butane-1-sulfonate ((eo)2Im+(CH2)4SO3–), 3-(1-(2-(2-methoxyethoxy)ethyl)-1H-imidazol-3-ium-3-yl)propane-1-sulfonate ((eo)2Im+(CH2)3SO3–), 3-(1-(2-(2-methoxyethoxy)ethyl)-1H-imidazol-3-ium-3-yl)propane-1-sulfonate((eo)3Im+(CH2)3SO3–), and 3-(1-(2,5,8,11,14,17,20-heptaoxadocosan-22-yl)-1H-imidazol-3-ium-3-yl)propane-1-sulfonate ((eo)7Im+(CH2)3SO3–) in both zwitterionic and ionic forms; the ionic forms were generatedby protonating the ZwILs with trifluoromethanesulfonic acid (triflicacid, TA). The data show that the direct piezoelectric responses ofthe zwitterionic forms are small relative to the response of the referenceionic liquid, 1-butylpyridin-1-ium bis((trifluoromethyl)sulfonyl)imide(C4Py TFSI), and that the ionic (protonated) forms of theZwILs exhibit a piezoelectric response that depends on the extentof protonation. We relate these results to the structure-dependentdipolar properties of the species and to how these properties influencethe pressure-induced crystallization process required to manifestthe direct piezoelectric effect in liquids.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11913–11919"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Post-Translationally Generated Cysteine-Sulfonate Functions as a Ligand in the Oxygen-Evolving Complex of Photosystem II 翻译后生成的半胱氨酸磺酸盐作为配体在光系统II的氧演化复合物中的作用

IF 3.2 2区化学

The Journal of Physical Chemistry B Pub Date : 2026-11-05 Epub Date: 2026-10-26 DOI: 10.1021/acs.jpcb.6c06248

Kazuha Nakamura, Takehiro Suzuki, Hatsune Mizue, Tomomi Kitajima-Ihara, Minako Hirano, Yuki Kato, Naoshi Dohmae, Takumi Noguchi

{"title":"Post-Translationally Generated Cysteine-Sulfonate Functions as a Ligand in the Oxygen-Evolving Complex of Photosystem II","authors":"Kazuha Nakamura, Takehiro Suzuki, Hatsune Mizue, Tomomi Kitajima-Ihara, Minako Hirano, Yuki Kato, Naoshi Dohmae, Takumi Noguchi","doi":"10.1021/acs.jpcb.6c06248","DOIUrl":"https://doi.org/10.1021/acs.jpcb.6c06248","url":null,"abstract":"Photosyntheticoxygen evolution is catalyzed by the Mn4CaO5 cluster in the oxygen-evolving complex (OEC)of photosystemII. The Mn4CaO5 cluster is coordinated by sixcarboxylate ligands and one imidazole ligand derived from amino acidresidues. However, the precise roles of these amino acid ligands remainunclear. In this study, we genetically replaced a key carboxylateligand, D1-Asp170, with Cys and investigated the effects of this mutationon the structure and reactions of the OEC. Measurements of O2 evolution, together with thermoluminescence and delayed luminescenceanalyses, indicated that the Mn4CaO5 clusterwas formed in the D1-D170C mutant but exhibited low O2-evolvingactivity and markedly impaired S-state transitions beyond the S3 state. LC–MS analysis revealed that D1-Cys170 in themutant was completely oxidized to cysteine sulfonic acid (Cys-SO3H). Quantum mechanics/molecular mechanics (QM/MM) calculationsfurther demonstrated that the resulting cysteine sulfonate (Cys-SO3–) functions as a bridging ligand betweenthe Mn and Ca ions, replacing the carboxylate group of Asp. This representsa unique example of an amino acid-derived sulfonate group servingas a ligand to the Mn4CaO5 cluster. The pronouncedfunctional effects of replacing the carboxylate with a sulfonate ligandhighlight the critical role of D1-Asp170 in regulating OEC reactions.","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":"130 44","pages":"11799–11808"},"PeriodicalIF":3.2,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149330246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0