{"title":"Retraction Note: Impacts of particles' aspect ratio on the efficacy of β-FeOOH nanorods as nano-based oral iron supplements.","authors":"Erfan Haghighatseir, Reza Heidari, Nazanin Sabet-Eghlidi, Zeinab Karimi, Aydin Berenjian, Alireza Ebrahiminezhad","doi":"10.1007/s00775-026-02179-4","DOIUrl":"https://doi.org/10.1007/s00775-026-02179-4","url":null,"abstract":"","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matheus Reis Santos de Melo, Arthur Barcelos Ribeiro, Marcela de Melo Junqueira, Natália Nascimento Silveira, Raquel Alves Dos Santos, Marcos V Palmeira-Mello, Alzir Azevedo Batista, Denise Crispim Tavares
{"title":"Ruthenium(II) coordinated with diphenylphosphine and 2-mercaptothiazoline as a selective antiproliferative agent in breast cancer cells.","authors":"Matheus Reis Santos de Melo, Arthur Barcelos Ribeiro, Marcela de Melo Junqueira, Natália Nascimento Silveira, Raquel Alves Dos Santos, Marcos V Palmeira-Mello, Alzir Azevedo Batista, Denise Crispim Tavares","doi":"10.1007/s00775-026-02178-5","DOIUrl":"https://doi.org/10.1007/s00775-026-02178-5","url":null,"abstract":"<p><p>Breast cancer is the most common malignant neoplasm among women and exhibits high molecular heterogeneity, which directly influences therapeutic response and clinical outcomes. Despite advances in targeted therapies and immunotherapies, tumor recurrence, resistance to conventional treatments, and metastatic potential reinforce the need for more selective and effective pharmacological strategies. In this context, metal complexes, particularly ruthenium(II) derivatives, have attracted considerable attention due to their antitumor profile, greater selectivity, and lower systemic toxicity. Therefore, in the present study, the antineoplastic activity of the RuMTZ complex (2-mercaptothiazoline-di-1,2-bis(diphenylphosphine)ethane-ruthenium(II)) was evaluated in three breast cancer cell lines (MDA-MB-231, MDA-MB-468 and MCF7) and in one non-tumor breast cell line (MCF10A). RuMTZ exhibited greater cytotoxicity against human MDA-MB-468 cells, as demonstrated by cell viability (IC<sub>50</sub> = 1.8 µM) and clonogenic (IC<sub>50</sub> = 0.08 µM) assays, associated with higher selectivity indexes (3.89 and 3.75, respectively). Further studies demonstrated that RuMTZ inhibited cell migration by up to 62.76% and induced cell-cycle arrest in the G0/G1 phase, accompanied by a reduction in the G2/M population. Furthermore, the ruthenium complex induced apoptotic cell death, as observed by flow cytometry and increased levels of cleaved caspase-3 by Western blot. The genotoxic effect of RuMTZ was evidenced by the comet assay and increased γH2AX expression levels. Taken together, these findings demonstrate that RuMTZ exhibits promising antineoplastic activity against breast cancer cells, associated with cell-cycle arrest, induction of DNA damage, and apoptosis.</p>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149284423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Redox regulation in O<sub>2</sub> -tolerant [FeFe] hydrogenases: insights from two homologues.","authors":"Rinat Khundoker, Sean Majer, Alexey Silakov","doi":"10.1007/s00775-026-02177-6","DOIUrl":"https://doi.org/10.1007/s00775-026-02177-6","url":null,"abstract":"<p><p>O<sub>2</sub>-tolerance is a desirable property for [FeFe] hydrogenases, which are highly efficient H<sub>2</sub>-producing catalysts. While most such enzymes are highly sensitive to aerobic environments, a small number of explored representatives exhibit exceptional stability and even H<sub>2</sub>-producing activity under oxygenic conditions. However, the genetic signatures of the O<sub>2</sub>-tolerance in this class of enzymes remain largely unknown. To address this knowledge gap, we explored a close homologue of a well-characterized O<sub>2</sub>-tolerant [FeFe] hydrogenase from Clostridium beijerinckii (CbHydA1)-a hydrogenase from Terrisporobacter glycolicus (TgHydA1). Our investigation indeed confirms that TgHydA1 can transition to the O<sub>2</sub>-stable H<sub>inact</sub> state, a hallmark of O<sub>2</sub> tolerance. The surprising outcome is that despite the high amino acid similarity, TgHydA1 shows a substantially higher propensity to remain in the H<sub>inact</sub> state than CbHydA1. Using protein film electrochemical experiments, we demonstrate that the root of this behavior lies in roughly tenfold slower reactivation rates than those of CbHydA1 at any applied potential. This degree and direction of variation in reactivation kinetics have not been observed before for any other O<sub>2</sub>-tolerant [FeFe] hydrogenases or their variants to date, uncovering a yet-to-be-explored facet of reactivity alteration available to these enzymes. Overall, the results presented here highlight the importance of a holistic analysis of [FeFe] hydrogenase sequences in the context of their interaction with O<sub>2</sub> that encompasses the protein environment and properties of the auxiliary metallocofactors.</p>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cuproptosis and the bioinorganic basis of copper-induced cell death.","authors":"Yijian Qiu, Michael J Lukey","doi":"10.1007/s00775-026-02175-8","DOIUrl":"https://doi.org/10.1007/s00775-026-02175-8","url":null,"abstract":"<p><p>Copper is an essential yet potentially toxic biological trace element, whose functions in cells arise from its unique redox and coordination chemistry. The same chemical properties that make copper indispensable for a variety of fundamental biological processes, including respiration and antioxidant defense, also render it highly toxic when intracellular concentrations exceed homeostatic levels. Recently, a copper-dependent form of regulated cell death (RCD) termed cuproptosis has been identified, in which excess copper triggers cytotoxicity by directly binding the metabolic machinery of mitochondria to induce proteotoxic stress. Hallmark features of cuproptosis include the high-affinity coordination of copper with lipoylated proteins and the destabilization of iron-sulfur (Fe-S) cluster enzymes within the mitochondrial matrix, which together trigger metabolic dysfunction and protein aggregation that ultimately lead to cell death. Cuproptosis thus represents the first RCD pathway whose execution depends directly on metal-protein coordination chemistry. Emerging evidence indicates that cuproptosis may contribute to the pathogenesis of a variety of human diseases including cancer, neurodegeneration, and genetic disorders of copper metabolism. A precise mechanistic understanding of this form of RCD therefore has the potential to reveal new opportunities for therapeutic intervention. Here, we examine the bioinorganic basis of cuproptosis, its intersections with cellular copper handling systems, its role in disease processes, and the potential therapeutic strategies that aim to exploit this pathway for clinical benefit.</p>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149102518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexandra Mânzat, Nicoleta Andrian, Cezara Zăgrean-Tuza, Dan Porumb, Radu Silaghi-Dumitrescu
{"title":"Spectroscopic evaluation of the interaction of myoglobin with biomedically relevant compounds.","authors":"Alexandra Mânzat, Nicoleta Andrian, Cezara Zăgrean-Tuza, Dan Porumb, Radu Silaghi-Dumitrescu","doi":"10.1007/s00775-026-02176-7","DOIUrl":"https://doi.org/10.1007/s00775-026-02176-7","url":null,"abstract":"<p><p>Reported here is an investigation of the redox behavior of myoglobin (Mb) in the presence of several bioactive compounds with biomedical relevance. These include the well-known Pt(II) drug, cisplatin, oxoplatin (a Pt(IV) compound representative for a newer-generation drugs based on platinum), capric acid, fenbufen, plumbagin and fisetin. These molecules were selected based on their structural diversity and documented biological effects, such as anti-inflammatory, chemotherapeutic, or antioxidant properties. The study aimed to evaluate how these compounds affect the structural and redox properties of Mb, particularly in terms of their capacity to bind to the protein and modulate its oxidation state. Spectroscopic and computational methods (UV-Vis absorption, fluorescence, NMR, molecular docking and molecular dynamics) were used to monitor binding and modifications of the redox state of the Mb in reactions such as autoxidation, nitrite-induced autoxidation, and peroxide-induced damage. These experiments are designed to parallel previous findings with similar experiments on hemoglobin with small molecules of biomedical/therapeutic relevance. While some compounds induced minimal or no spectral changes - suggesting limited interaction or redox impact, others displayed distinct redox effects, with plumbagin promoting oxidation while fisetin exerted a stabilizing, protective influence on the oxygenated form of myoglobin. These findings suggest that plumbagin may act as pro-oxidant by promoting myoglobin oxidation, whereas fisetin interacts with Mb in a manner that stabilizes the oxygenated form and mitigates oxidative conversion. The observed variability highlights the complex nature of small molecule-protein interactions and underlines the importance of assessing individual compound behavior in biochemical systems.</p>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149102582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luca Famlonga, Lorenzo Chiaverini, Jana Timotijević, Ana Kandić, Stefan R Nikolić, Antoine Dupé, Simona M Sigona, Elisabetta Barresi, Chiara Giacomelli, Ljiljana E Mihajlović, Tiziano Marzo, Jelena Poljarević
{"title":"Tailoring the biological activity of oxorhenium(V) complexes through Chrysin ligand functionalization.","authors":"Luca Famlonga, Lorenzo Chiaverini, Jana Timotijević, Ana Kandić, Stefan R Nikolić, Antoine Dupé, Simona M Sigona, Elisabetta Barresi, Chiara Giacomelli, Ljiljana E Mihajlović, Tiziano Marzo, Jelena Poljarević","doi":"10.1007/s00775-026-02174-9","DOIUrl":"https://doi.org/10.1007/s00775-026-02174-9","url":null,"abstract":"<p><p>Chrysin, structurally one of the simplest flavonoids, shows a broad spectrum of biological activities, particularly its anticancer potential. Additionally, it has the possibility of coordination to metal ions as a bidentate chelate ligand, forming highly stable metal complexes. This synergism of metal ions and Chrysin led to a significant improvement in its diverse biological activities. Chrysin (HL1) and its derivatives (methoxy (HL2), benzyloxy (HL3), acetylated (HL4), and silylated (HL5)) were coordinated as OO-bidentate ligands to the rhenium(V) ion, and all five complexes crystallized in the form of monocrystals. The stability studies in PBS and human blood plasma solution were performed for those compounds, indicating that all complexes underwent precipitation in PBS, whereas no precipitation was observed in plasma. Moreover, the spectral profiles recorded in plasma indicate that plasma components exert a significant stabilizing effect on the rhenium complexes. The antiproliferative activity of complexes 1-5 was evaluated against the human ovarian carcinoma (A2780), colorectal carcinoma (HCT116), and the non-malignant HEK293 cell line. No direct relationship could be established between the complex precipitation in plasma and its cytotoxic activity. Complex 3 displayed pronounced spectral modifications in plasma while remaining essentially inactive in all cell lines tested, whereas 1 exhibited comparatively limited spectral changes despite being among the most active compounds of the series. The most active complexes 5, 1, and 2 displayed significant selectivity, with lower cytotoxicity toward non-tumorigenic HEK293 cells than A2780 and HCT116 cancer cells.</p>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149102566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lara Callea, Carla Orlando, Claudio Greco, Gioele Fumagalli, Andrea Fasano, Luca De Gioia, Federica Arrigoni, Luca Bertini
{"title":"Exploring the role of oxidative defects in polyethylene binding and degradation by a Rhodococcus opacus R7 multicopper oxidase: a computational perspective.","authors":"Lara Callea, Carla Orlando, Claudio Greco, Gioele Fumagalli, Andrea Fasano, Luca De Gioia, Federica Arrigoni, Luca Bertini","doi":"10.1007/s00775-026-02173-w","DOIUrl":"https://doi.org/10.1007/s00775-026-02173-w","url":null,"abstract":"<p><p>The enzymatic degradation of polyethylene (PE) by oxidative enzymes remains poorly understood at the molecular level, limiting the development of effective biotechnological strategies for plastic valorization. Here, we investigate the molecular basis of PE oxidation by the laccase-like multicopper oxidase LMCO2 from Rhodococcus opacus R7 with combined DFT and molecular docking calculations. LMCO2 is a particularly relevant model system because it has been experimentally shown to oxidatively modify low-density polyethylene without the need for mediators, despite its relatively low redox potential. DFT calculations indicate that direct oxidation of aliphatic C-H bonds in pristine PE is energetically prohibitive, and that hydroxylated defects do not significantly facilitate substrate activation. In contrast, oxidation at carbon atoms adjacent to carbonyl groups is associated with substantially lower barriers, owing to stabilization of the resulting radicals through conjugation and keto-enol tautomerism. Alternative pathways involving alkoxyl radicals and β-scission were also examined and found to be energetically unfavorable. Molecular docking calculations complement this picture by showing that both pristine and pre-oxidized PE segments can access the main cavity adjacent to the T1 copper site, although binding is weak and largely non-specific. Taken together, these results support a mechanism in which LMCO2 selectively acts on pre-oxidized, carbonyl-containing regions of polyethylene, promoting further radical chemistry that may ultimately lead to chain scission and the formation of low-molecular-weight oxygenated products.</p>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149007850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Current clinical applications and future developments of platinum-based anticancer drugs","authors":"Maria S. Kamusheva, Hristo P. Varbanov","doi":"10.1007/s00775-026-02172-x","DOIUrl":"10.1007/s00775-026-02172-x","url":null,"abstract":"<div><p>The study evaluated the current patterns of guideline-recommended clinical use, real-world utilization trends, and translational development of platinum-based (Pt-based) drugs through a comparative analysis of national and international pharmacotherapeutic guidelines, national drug utilization data, clinical trials, and emerging research directions. Cisplatin, carboplatin and oxaliplatin continue to play central roles across multiple malignancies and remain widely incorporated into recommended treatment protocols. Across all five guideline sources evaluated, Pt-based therapies were recommended in more than half of the 18 ICD-O topographic categories, with guideline coverage ranging from 55.6% to 83.3%. Real-world utilization data, using Bulgaria as a case study, indicated sustained and increasing use of Pt-based therapies between 2021 and 2024, with oxaliplatin showing the greatest increase. Current clinical trials focus primarily on optimizing established Pt-based regimens through combinations with immunotherapeutics and emerging drug candidates within increasingly personalized multimodal treatment strategies. In parallel, research efforts are directed toward the development of new Pt complexes, exploring next-generation approaches such as multifunctional Pt(IV) prodrugs and Pt–N–heterocyclic carbene compounds, as well as advanced drug-delivery systems, reflecting continued innovation in the field. Overall, Pt-based drugs remain essential in cancer therapy and continue to represent a dynamic area of research in biological inorganic chemistry and translational oncology.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"31 6","pages":"469 - 488"},"PeriodicalIF":2.8,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-026-02172-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148917953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jack Silver, Jehad A Taies, Husam M Abu-Soud, George R. Fern
{"title":"Protoporphyrin IX iron(II) revisited. overview ofthe Mössbauer spectroscopic parameters of low spin porphyrin iron(II) complexes Part II","authors":"Jack Silver, Jehad A Taies, Husam M Abu-Soud, George R. Fern","doi":"10.1007/s00775-026-02158-9","DOIUrl":"10.1007/s00775-026-02158-9","url":null,"abstract":"<div><p>Mössbauer parameters of low spin six coordinate [Fe(II)(Por)L<sub>2</sub>] and [Fe(II)(Por)LX] complexes (where Por is PPIX or a synthetic porphyrin; L is OH<sup>−</sup>, H<sub>2</sub>O, a nitrogenous base, CCl<sub>2</sub>, CO or CN<sup>−</sup> and X is a different ligand to L) are discussed. Our point charge calculation approach is extended to investigate how the axial ligands and the four porphyrinato-N atoms generate the observed quadrupole splittings (ΔE<sub>Q</sub>). Partial quadrupole splitting (p.q.s.) and partial centre shift (p.c.s.) values are derived and discussed for all the axial ligands studied herein. It is shown that when the D<sub>4h</sub> symmetry breaks down due to porphyrin ring ruffling, the point charge calculations no longer apply. This happens for many synthetic porphyrins but not for the uniquely important [Fe(II)(PPIX)] moiety, (which is ubiquitous in nature). Thus, synthetic porphyrins (like TPP) cannot always act as perfect proxies for natural haem proteins. In all the haem proteins containing [Fe(II)(PPIX)] moieties the haem is planar. Calculations indicate that if H<sub>2</sub>O were bound to the [Fe(II)(PPIX))] present in deoxyhaemoglobin or deoxy myoglobin, then these Fe(II) atoms would be low spin. In contrast for synthetic and natural haem proteins containing haem b (where the haem is connected to the protein backbone via two cysteine residues) the haem plane is ruffled (probably because of the methionine linkages transferring force and controlling the stereochemistry of the haem plane, and thereby its chemistry). For the [Fe(II)(TPP)(CN)<sub>2</sub>] and [Fe(II)(TPP)(1-MeIm)(CN)] the calculated CN<sup>−</sup> ligand p.q.s values are suspect and probably show that the lattice charge is affecting them.</p></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"31 6","pages":"451 - 468"},"PeriodicalIF":2.8,"publicationDate":"2026-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-026-02158-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148890658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Julia Seifermann, Lorena Ilcu, Céline Moog, Lin Zhang, Oliver Einsle
{"title":"Heme handling in the system II heme lyase CcsBA from Bacteroides thetaiotaomicron","authors":"Julia Seifermann, Lorena Ilcu, Céline Moog, Lin Zhang, Oliver Einsle","doi":"10.1007/s00775-026-02171-y","DOIUrl":"10.1007/s00775-026-02171-y","url":null,"abstract":"<div><p>Cytochrome <i>c</i> biogenesis in bacteria relies on complex membrane-bound machineries that facilitate the covalent attachment of heme to apocytochrome <i>c</i>. System II, mediated by the bifunctional protein CcsBA, is prevalent in Gram-positive and some Gram-negative bacteria, as well as chloroplasts. Here, we report a 2.9 Å resolution cryo-EM structure of a W703C mutant of CcsBA from <i>Bacteroides thetaiotaomicron</i>, revealing its conformation in the heme-loaded, closed state. Comparative analysis with the previously published <i>Helicobacter hepaticus</i> CcsBA structure shows a conserved membrane architecture and WxWD domain organization, but notable differences in the arrangement of the periplasmic domain and the active site configuration. The W703C mutation allowed heme occupancy in the active site without inducing the open conformation, implicating the native W703 in regulating structural transitions critical for heme attachment. Our findings suggest that while the open conformation facilitates heme ligation, it is not essential for heme translocation. This work expands the understanding of structure–function relationships in System II cytochrome <i>c</i> maturation and highlights the potential regulatory role of the periplasmic domain conformational dynamics.</p></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"31 6","pages":"567 - 576"},"PeriodicalIF":2.8,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-026-02171-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148817068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}