Pub Date : 2025-10-11DOI: 10.1016/j.jinorgbio.2025.113110
Jincan Chen , Jie Gao , Liang Hao , Qing Guo , Xiang Chen , Fengkai Cai , Zhiyi Li , Jia Zheng , Xufeng Zhu , Lanmei Chen
Antimicrobial resistance in Staphylococcus aureus (S. aureus) significantly increases both the mortality rate and the difficulty of treatment, highlighting the urgent need for new antimicrobial agents. In this study, two polypyridyl biguanide ruthenium complexes-[Ru(phen)2TolBig](PF6)2 (Ru1) and [Ru(tmp)2TolBig](PF6)2 (Ru2), were synthesized and found to exhibit photodynamic antibacterial activity, with Ru2 demonstrating the most potent effect. In vitro antimicrobial screening showed that both Ru1 and Ru2 effectively inhibited the growth of Gram-positive bacteria, including methicillin-resistant S. aureus (MRSA). Mechanistic investigations revealed that Ru2 under light irradiation (Ru2 + L) generated elevated levels of reactive oxygen species (ROS), leading to redox imbalance, lipid peroxidation, and a ferroptosis-like bacterial cell death. Additionally, Ru2 + L disrupted bacterial cell membranes and induced “bubbling cell death.” Notably, Ru2 exhibited a multi-pathway antibacterial mechanism, which helped reduce the development of bacterial resistance. In vivo experiments further confirmed that Ru2 could accelerate wound healing with minimal physiological toxicity. This study not only expands the antimicrobial potential of biguanide derivatives but also offers a novel strategy for developing multi-pathway antimicrobial agents.
{"title":"Polypyridyl biguanide ruthenium complex induces photodynamic membrane damage, ferroptosis-like bacterial death, and “bubbling cell death”","authors":"Jincan Chen , Jie Gao , Liang Hao , Qing Guo , Xiang Chen , Fengkai Cai , Zhiyi Li , Jia Zheng , Xufeng Zhu , Lanmei Chen","doi":"10.1016/j.jinorgbio.2025.113110","DOIUrl":"10.1016/j.jinorgbio.2025.113110","url":null,"abstract":"<div><div>Antimicrobial resistance in <em>Staphylococcus aureus</em> (<em>S. aureus</em>) significantly increases both the mortality rate and the difficulty of treatment, highlighting the urgent need for new antimicrobial agents. In this study, two polypyridyl biguanide ruthenium complexes-[Ru(phen)<sub>2</sub>TolBig](PF<sub>6</sub>)<sub>2</sub> (<strong>Ru1</strong>) and [Ru(tmp)<sub>2</sub>TolBig](PF<sub>6</sub>)<sub>2</sub> (<strong>Ru2</strong>), were synthesized and found to exhibit photodynamic antibacterial activity, with <strong>Ru2</strong> demonstrating the most potent effect. <em>In vitro</em> antimicrobial screening showed that both <strong>Ru1</strong> and <strong>Ru2</strong> effectively inhibited the growth of Gram-positive bacteria, including methicillin-resistant <em>S. aureus</em> (MRSA). Mechanistic investigations revealed that <strong>Ru2</strong> under light irradiation (<strong>Ru2 + L</strong>) generated elevated levels of reactive oxygen species (ROS), leading to redox imbalance, lipid peroxidation, and a ferroptosis-like bacterial cell death. Additionally, <strong>Ru2 + L</strong> disrupted bacterial cell membranes and induced “bubbling cell death.” Notably, <strong>Ru2</strong> exhibited a multi-pathway antibacterial mechanism, which helped reduce the development of bacterial resistance. <em>In vivo</em> experiments further confirmed that <strong>Ru2</strong> could accelerate wound healing with minimal physiological toxicity. This study not only expands the antimicrobial potential of biguanide derivatives but also offers a novel strategy for developing multi-pathway antimicrobial agents.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"274 ","pages":"Article 113110"},"PeriodicalIF":3.2,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306591","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}
Pub Date : 2025-10-10DOI: 10.1016/j.jinorgbio.2025.113106
Meghan B. Mouton , Olivia Browne , Breanna G. Bailey, Heather R. Williamson
Myoglobin Compound II auto-reduction has been hypothesized to be sequential proton transfer followed by an electron transfer rate-limited via the protonation of the ferryl oxo with a pKa ≤ 2.7 via various spectroscopic techniques or 4.7 via UV–Visible spectroscopy and kinetic studies. However, by exploring the subtle pH and temperature dependence of kobs, we have found the Compound II auto-reduction to be best modeled with a pre-equilibrium proton transfer that includes both the sequential proton electron transfer and concerted proton-coupled electron transfer, gated by the distal Histidine64 as a proton donor. Parameters from the temperature dependence studies allow an extension of the proposed proton-coupled electron transfer model to fit the kobs to over full temperature range of 20⎼50 °C.
{"title":"Proton coupled electron transfer in myoglobin compound II auto-reduction revealed by temperature dependent rate behavior","authors":"Meghan B. Mouton , Olivia Browne , Breanna G. Bailey, Heather R. Williamson","doi":"10.1016/j.jinorgbio.2025.113106","DOIUrl":"10.1016/j.jinorgbio.2025.113106","url":null,"abstract":"<div><div>Myoglobin Compound II auto-reduction has been hypothesized to be sequential proton transfer followed by an electron transfer rate-limited via the protonation of the ferryl oxo with a pK<sub>a</sub> ≤ 2.7 via various spectroscopic techniques or 4.7 via UV–Visible spectroscopy and kinetic studies. However, by exploring the subtle pH and temperature dependence of k<sub>obs</sub>, we have found the Compound II auto-reduction to be best modeled with a pre-equilibrium proton transfer that includes both the sequential proton electron transfer and concerted proton-coupled electron transfer, gated by the distal Histidine64 as a proton donor. Parameters from the temperature dependence studies allow an extension of the proposed proton-coupled electron transfer model to fit the k<sub>obs</sub> to over full temperature range of 20⎼50 °C.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113106"},"PeriodicalIF":3.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145413853","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}
{"title":"Corrigendum to “The thiolation of U34 at carbon 2 in tRNA by Escherichia coli MnmA precedes modification at carbon 5 and is dependent on a [4Fe4S] cluster” J Inorg Biochem 2026, vol 274, 113064–113072/ JIB_113064","authors":"Sylvain Gervason , Sambuddha Sen , Jingjing Zhou , Marouane Libiad , Karolina Podskoczyj , Grazyna Leszczynska , Sylvain Caillat , Jean-Luc Ravanat , Marc Fontecave , Béatrice Golinelli-Pimpaneau","doi":"10.1016/j.jinorgbio.2025.113096","DOIUrl":"10.1016/j.jinorgbio.2025.113096","url":null,"abstract":"","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"274 ","pages":"Article 113096"},"PeriodicalIF":3.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273464","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}
Pub Date : 2025-10-10DOI: 10.1016/j.jinorgbio.2025.113103
Rosanna Cuccaro , Martina Masini , José Malanho Silva , Francesca Camponeschi , Lucia Banci
Human cytosolic monothiol glutaredoxin-3 (GLRX3) plays a central role in the maturation of cytosolic [4Fe–4S] proteins by acting as a [2Fe2S] cluster donor to early components of the cytosolic iron–sulfur assembly (CIA) machinery, including the P-loop NTPase nucleotide-binding protein 1 (NUBP1). While previous studies have established that dimeric, cluster-bridged GLRX3 transfers its [2Fe–2S]2+ clusters to NUBP1 promoting the formation of the [4Fe4S]2+ cluster, the determinants within GLRX3 that enable this transfer remain unclear. Here, we analyze the specific contribution of each GLRX3 domain—glutaredoxin A (GrxA), glutaredoxin B (GrxB), and thioredoxin-like (Trx)—to the transfer of [2Fe–2S] clusters to NUBP1. We show in vitro that a cooperative mechanism between the two cluster-binding domains, GrxA and GrxB, is essential for the formation of a functional dimeric GLRX3 complex capable of efficient cluster transfer and for the assembly of the [4Fe4S] cluster on NUBP1. In contrast, the Trx domain appears dispensable for this activity in these experimental conditions. These findings may provide new insights into the features underlying GLRX3 function in cytosolic [4Fe–4S] cluster biogenesis and highlight the domain-specific contributions to its role as a [2Fe2S] cluster chaperone.
人细胞质单硫醇glutaredoxin-3 （GLRX3）在细胞质[4Fe-4S]蛋白的成熟过程中发挥核心作用，作为细胞质铁硫组装（CIA）机制的早期组分（包括p环NTPase核苷酸结合蛋白1 (NUBP1)）的[2Fe2S]簇供体。虽然先前的研究已经确定二聚体簇桥接GLRX3将其[2Fe-2S]2+簇转移到NUBP1上，促进[4Fe4S]2+簇的形成，但GLRX3内部实现这种转移的决定因素尚不清楚。在这里，我们分析了每个GLRX3结构域-glutaredoxin A (GrxA), glutaredoxin B （GrxB）和thioredoxin-like (Trx)-对[2Fe-2S]簇向NUBP1转移的具体贡献。我们在体外实验中发现，GrxA和GrxB两个簇结合结构域之间的合作机制对于形成能够有效簇转移的功能性二聚体GLRX3复合物以及[4Fe4S]簇在NUBP1上的组装至关重要。相反，在这些实验条件下，Trx结构域对于这种活性似乎是可有可无的。这些发现可能为GLRX3在细胞质[4Fe-4S]簇生物发生中的功能提供了新的见解，并突出了其作为[2Fe2S]簇伴侣的作用的结构域特异性贡献。
{"title":"Human glutaredoxin 3: multiple domains for a unique function","authors":"Rosanna Cuccaro , Martina Masini , José Malanho Silva , Francesca Camponeschi , Lucia Banci","doi":"10.1016/j.jinorgbio.2025.113103","DOIUrl":"10.1016/j.jinorgbio.2025.113103","url":null,"abstract":"<div><div>Human cytosolic monothiol glutaredoxin-3 (GLRX3) plays a central role in the maturation of cytosolic [4Fe–4S] proteins by acting as a [2Fe<img>2S] cluster donor to early components of the cytosolic iron–sulfur assembly (CIA) machinery, including the P-loop NTPase nucleotide-binding protein 1 (NUBP1). While previous studies have established that dimeric, cluster-bridged GLRX3 transfers its [2Fe–2S]<sup>2+</sup> clusters to NUBP1 promoting the formation of the [4Fe<img>4S]<sup>2+</sup> cluster, the determinants within GLRX3 that enable this transfer remain unclear. Here, we analyze the specific contribution of each GLRX3 domain—glutaredoxin A (GrxA), glutaredoxin B (GrxB), and thioredoxin-like (Trx)—to the transfer of [2Fe–2S] clusters to NUBP1. We show in vitro that a cooperative mechanism between the two cluster-binding domains, GrxA and GrxB, is essential for the formation of a functional dimeric GLRX3 complex capable of efficient cluster transfer and for the assembly of the [4Fe<img>4S] cluster on NUBP1. In contrast, the Trx domain appears dispensable for this activity in these experimental conditions. These findings may provide new insights into the features underlying GLRX3 function in cytosolic [4Fe–4S] cluster biogenesis and highlight the domain-specific contributions to its role as a [2Fe<img>2S] cluster chaperone.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"274 ","pages":"Article 113103"},"PeriodicalIF":3.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145297779","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}
Pub Date : 2025-10-10DOI: 10.1016/j.jinorgbio.2025.113108
Rebecca K. Zawistowski, James C. Clark, Brian R. Crane
The complex between cytochrome c peroxidase (CcP) and cytochrome c (Cc) is an important model system for studying interprotein electron transfer (ET). Low ionic strength conditions stabilize the CcP:Cc complex, but promote unfavorable second-site binding of Cc. Conversely, high ionic strengths favor the 1:1 complex but promote its dissociation. We sought to stabilize the complex and minimize second-site binding by linking the two proteins together via sortase-mediated transpeptidation. Ligation efficiency of the two proteins depends on the length of the flexible linker and the conditions of the ligation reaction. Structural comparisons and AI-based predictions indicate that the conformations assumed by the fusion proteins depend substantially on the linker length. A short linker allows the association mode found in the 1:1 non-covalent complex but favors more extended states. Longer linkers are more conducive to productive complex formation but still sample other conformational states that disfavor interprotein ET. The degree of predicted conformational variation in the fusion proteins agrees well with their ET reactivity and structural analyses by crystallography and small-angle x-ray scattering. Our findings underscore that specific interaction modes between redox partners influence their electronic communication and reveal that interdomain linkers have the potential to control intermolecular reactions and alter the sampling of productive interfaces.
{"title":"Sortase-mediated ligation of cytochrome c peroxidase and cytochrome c highlights the roles of dynamics and conformational specificity for interprotein electron transfer","authors":"Rebecca K. Zawistowski, James C. Clark, Brian R. Crane","doi":"10.1016/j.jinorgbio.2025.113108","DOIUrl":"10.1016/j.jinorgbio.2025.113108","url":null,"abstract":"<div><div>The complex between cytochrome <em>c</em> peroxidase (CcP) and cytochrome <em>c</em> (Cc) is an important model system for studying interprotein electron transfer (ET). Low ionic strength conditions stabilize the CcP:Cc complex, but promote unfavorable second-site binding of Cc. Conversely, high ionic strengths favor the 1:1 complex but promote its dissociation. We sought to stabilize the complex and minimize second-site binding by linking the two proteins together via sortase-mediated transpeptidation. Ligation efficiency of the two proteins depends on the length of the flexible linker and the conditions of the ligation reaction. Structural comparisons and AI-based predictions indicate that the conformations assumed by the fusion proteins depend substantially on the linker length. A short linker allows the association mode found in the 1:1 non-covalent complex but favors more extended states. Longer linkers are more conducive to productive complex formation but still sample other conformational states that disfavor interprotein ET. The degree of predicted conformational variation in the fusion proteins agrees well with their ET reactivity and structural analyses by crystallography and small-angle x-ray scattering. Our findings underscore that specific interaction modes between redox partners influence their electronic communication and reveal that interdomain linkers have the potential to control intermolecular reactions and alter the sampling of productive interfaces.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"274 ","pages":"Article 113108"},"PeriodicalIF":3.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145317954","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}
Pub Date : 2025-10-10DOI: 10.1016/j.jinorgbio.2025.113109
Monica Caselli , Lorenzo Sebastianelli , Mirco Meglioli , Gianantonio Battistuzzi , Marco Borsari
Human neuroglobin (hNgb) is a globin involved in the protection of neurons and retinal cells which features an intramolecular disulfide bond between Cys46 and Cys55 under oxidative conditions. Here, conformational changes and oxidative degradation of hNgb wt and its C46AC55A mutant, lacking the disulfide bridge, were investigated in the presence of sodium dodecyl sulfate (SDS) by electronic absorption spectroscopy, intrinsic fluorescence emission and circular dichroism. Both proteins are found to undergo multiple SDS-induced conformational changes resulting in the formation of two non-native high spin species (HS1 and HS2). Moreover, increasing SDS concentration enhances the rate of heme breakdown by H2O2. Deletion of the Cys46-Cys55 disulfide bridge amplifies the conformational effect of SDS and appreciably increases heme oxidative degradation by H2O2.
{"title":"Influence of the intramolecular disulfide Cys46-Cys55 bridge on the interaction of human neuroglobin with SDS","authors":"Monica Caselli , Lorenzo Sebastianelli , Mirco Meglioli , Gianantonio Battistuzzi , Marco Borsari","doi":"10.1016/j.jinorgbio.2025.113109","DOIUrl":"10.1016/j.jinorgbio.2025.113109","url":null,"abstract":"<div><div>Human neuroglobin (hNgb) is a globin involved in the protection of neurons and retinal cells which features an intramolecular disulfide bond between Cys46 and Cys55 under oxidative conditions. Here, conformational changes and oxidative degradation of hNgb wt and its C46AC55A mutant, lacking the disulfide bridge, were investigated in the presence of sodium dodecyl sulfate (SDS) by electronic absorption spectroscopy, intrinsic fluorescence emission and circular dichroism. Both proteins are found to undergo multiple SDS-induced conformational changes resulting in the formation of two non-native high spin species (HS1 and HS2). Moreover, increasing SDS concentration enhances the rate of heme breakdown by H<sub>2</sub>O<sub>2</sub>. Deletion of the Cys46-Cys55 disulfide bridge amplifies the conformational effect of SDS and appreciably increases heme oxidative degradation by H<sub>2</sub>O<sub>2</sub>.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"274 ","pages":"Article 113109"},"PeriodicalIF":3.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306615","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}
Pub Date : 2025-10-10DOI: 10.1016/j.jinorgbio.2025.113094
Celeste Guillen , Leonardo J. Monroy-Cruz , Kiara Aricoche-Del Campo , Mirko Zimic , Paloma Salas
Tuberculosis (TB) remains one of the deadliest bacterial infections, despite the approval of new anti-bacterial drugs over the past decade. This persistent challenge is attributed to the emergence of drug-resistant Mycobacterium tuberculosis strains, which emphasizes the ongoing need for novel therapeutic options. In this research, the synthesis and characterization of novel half-sandwich ruthenium (II) complexes featuring a quinoxaline-based ligand (L), 3-(4-bromophenyl)quinoxaline-2-carboxylic acid, are reported. The three complexes [Ru(p-cymene)(I)(L)] (1), [Ru(p-cymene)(Cl)(L)] (2) and [Ru(benzene)(Cl)(L)] (3) were characterized by FTIR, NMR and HRMS. Additionally, the solid-state structures of 1 and 2 were determined by XRD, revealing geometries similar to a three-legged piano stool, with the Ru atom coordinated to the carboxylate oxygen and the quinoxaline nitrogen atoms of the ligand. Interaction with mycobacterial drug targets was explored and binding energies based on docking scores were estimated to assess their potential antituberculous activity. Strong interactions were observed between 1 and 2 and the targets Emb complex and ATP synthase, suggesting potential antituberculous activity. Furthermore, the susceptibility of M. tuberculosis H37Rv strain to these compounds was evaluated by determining their minimum inhibitory concentrations (MICs). Compounds 2 and 3 each displayed MIC values of 50 μg/mL, whereas compound 1 exhibited a MIC of 100 μg/mL, which falls within the range observed for first-line drugs such as pyrazinamide. These findings confirm their activity against M. tuberculosis.
{"title":"Half-sandwich ruthenium (II) complexes with N,O-Quinoxaline ligand: Synthesis, in silico affinity and Mycobacterium tuberculosis susceptibility","authors":"Celeste Guillen , Leonardo J. Monroy-Cruz , Kiara Aricoche-Del Campo , Mirko Zimic , Paloma Salas","doi":"10.1016/j.jinorgbio.2025.113094","DOIUrl":"10.1016/j.jinorgbio.2025.113094","url":null,"abstract":"<div><div>Tuberculosis (TB) remains one of the deadliest bacterial infections, despite the approval of new anti-bacterial drugs over the past decade. This persistent challenge is attributed to the emergence of drug-resistant <em>Mycobacterium tuberculosis</em> strains, which emphasizes the ongoing need for novel therapeutic options. In this research, the synthesis and characterization of novel half-sandwich ruthenium (II) complexes featuring a quinoxaline-based ligand (<strong>L</strong>), 3-(4-bromophenyl)quinoxaline-2-carboxylic acid, are reported. The three complexes [Ru(<em>p</em>-cymene)(I)(L)] (<strong>1</strong>), <strong>[</strong>Ru(<em>p</em>-cymene)(Cl)(L)] (<strong>2</strong>) and <strong>[</strong>Ru(benzene)(Cl)(L)] (<strong>3</strong>) were characterized by FTIR, NMR and HRMS. Additionally, the solid-state structures of <strong>1</strong> and <strong>2</strong> were determined by XRD, revealing geometries similar to a three-legged piano stool, with the Ru atom coordinated to the carboxylate oxygen and the quinoxaline nitrogen atoms of the ligand. Interaction with mycobacterial drug targets was explored and binding energies based on docking scores were estimated to assess their potential antituberculous activity. Strong interactions were observed between <strong>1</strong> and <strong>2</strong> and the targets Emb complex and ATP synthase, suggesting potential antituberculous activity. Furthermore, the susceptibility of <em>M. tuberculosis H37Rv</em> strain to these compounds was evaluated by determining their minimum inhibitory concentrations (MICs). Compounds <strong>2</strong> and <strong>3</strong> each displayed MIC values of 50 μg/mL, whereas compound <strong>1</strong> exhibited a MIC of 100 μg/mL, which falls within the range observed for first-line drugs such as pyrazinamide. These findings confirm their activity against <em>M. tuberculosis</em>.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113094"},"PeriodicalIF":3.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145323567","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}
Pub Date : 2025-10-10DOI: 10.1016/j.jinorgbio.2025.113097
Mafalda V. Fernandes , Jorge M.A. Antunes , Carlos A. Salgueiro , Leonor Morgado
Electroactive bacteria mediate electron exchange with external compounds through a process known as extracellular electron transfer (EET). A key step in EET is the transfer of electrons from the menaquinone pool to inner membrane-associated quinol-cytochrome c oxidoreductase complexes, which subsequently relay electrons to periplasmic redox partners. Gene-knockout and proteomic analyses have identified several critical components involved in EET in Geobacter sulfurreducens, including six inner membrane oxidoreductase gene clusters. Of these, three - CbcL, ImcH, and CbcBA - have been linked to specific respiratory pathways depending on the redox potential of the terminal electron acceptor. Cbc4 is one of the other inner membrane oxidoreductase complexes and is composed by three subunits: a membrane-anchored tetraheme c-type cytochrome (CbcS), an iron–sulfur protein containing four [4Fe-4S] clusters (CbcT), and an integral membrane protein (CbcU). In this study, the sequence and AlphaFold model of CbcS were analyzed and its cytochrome domain was produced, and structurally and functionally characterized using Nuclear Magnetic Resonance spectroscopy. CbcS has four bis-histidine low-spin hemes and the structure of its hemecore is homologous to CymA and NrfH from Shewanella and Desulfovibrio species, respectively, despite differences on its axial ligands. Potentiometric titrations showed that the redox active window of CbcS overlaps with those of the triheme periplasmic cytochrome family (PpcA-E), its putative redox partners. Nevertheless, NMR-monitored electron transfer experiments revealed that CbcS transfers electrons to PpcA through the heme group closer to the C-terminal (heme IV). Together, these findings provide insights on a putative new respiratory pathway in G. sulfurreducens.
{"title":"Characterization of CbcS from Geobacter sulfurreducens' Cbc4 complex: a putative novel respiratory pathway","authors":"Mafalda V. Fernandes , Jorge M.A. Antunes , Carlos A. Salgueiro , Leonor Morgado","doi":"10.1016/j.jinorgbio.2025.113097","DOIUrl":"10.1016/j.jinorgbio.2025.113097","url":null,"abstract":"<div><div>Electroactive bacteria mediate electron exchange with external compounds through a process known as extracellular electron transfer (EET). A key step in EET is the transfer of electrons from the menaquinone pool to inner membrane-associated quinol-cytochrome <em>c</em> oxidoreductase complexes, which subsequently relay electrons to periplasmic redox partners. Gene-knockout and proteomic analyses have identified several critical components involved in EET in <em>Geobacter sulfurreducens</em>, including six inner membrane oxidoreductase gene clusters. Of these, three - CbcL, ImcH, and CbcBA - have been linked to specific respiratory pathways depending on the redox potential of the terminal electron acceptor. Cbc4 is one of the other inner membrane oxidoreductase complexes and is composed by three subunits: a membrane-anchored tetraheme <em>c</em>-type cytochrome (CbcS), an iron–sulfur protein containing four [4Fe-4S] clusters (CbcT), and an integral membrane protein (CbcU). In this study, the sequence and AlphaFold model of CbcS were analyzed and its cytochrome domain was produced, and structurally and functionally characterized using Nuclear Magnetic Resonance spectroscopy. CbcS has four bis-histidine low-spin hemes and the structure of its hemecore is homologous to CymA and NrfH from <em>Shewanella</em> and <em>Desulfovibrio</em> species, respectively, despite differences on its axial ligands. Potentiometric titrations showed that the redox active window of CbcS overlaps with those of the triheme periplasmic cytochrome family (PpcA-E), its putative redox partners. Nevertheless, NMR-monitored electron transfer experiments revealed that CbcS transfers electrons to PpcA through the heme group closer to the C-terminal (heme IV). Together, these findings provide insights on a putative new respiratory pathway in <em>G. sulfurreducens</em>.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"274 ","pages":"Article 113097"},"PeriodicalIF":3.2,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145312028","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}
Pub Date : 2025-10-09DOI: 10.1016/j.jinorgbio.2025.113105
Brisa Caroline Alves Chagas , Bjoern Brixius , Pang Che Wang , Somayeh Pirhadi , Ozha Aziz , David R. Koes , Elizabeth M.J. Gillam , Rita Bernhardt , Simone Brixius-Anderko
The cytochrome P450 enzyme 11A1 (CYP11A1) is the most important player in steroid hormone biosynthesis, catalysing the first and rate-limiting step, the side-chain cleavage of cholesterol to pregnenolone, which provides the precursor for all major steroid hormones. A resurrected ancestral isoform of CYP11A (CYP11A_N1) exhibits different substrate specificities to extant vertebrate CYP11A1 forms which implies an evolutionary change in structural features. Hence, we solved the structure of the resurrected ancestral CYP11A_N1 isoform and identified the major structural changes between ancestral and extant CYP11A isoforms that lead to different catalytic properties for cholesterol metabolism. Our work presents the first structure of an ancestral mitochondrial cytochrome P450 and highlights how structural changes shaped the evolution of steroid hormone biosynthesis.
{"title":"How evolution shaped the structure of steroidogenic cytochrome P450 11A","authors":"Brisa Caroline Alves Chagas , Bjoern Brixius , Pang Che Wang , Somayeh Pirhadi , Ozha Aziz , David R. Koes , Elizabeth M.J. Gillam , Rita Bernhardt , Simone Brixius-Anderko","doi":"10.1016/j.jinorgbio.2025.113105","DOIUrl":"10.1016/j.jinorgbio.2025.113105","url":null,"abstract":"<div><div>The cytochrome P450 enzyme 11A1 (CYP11A1) is the most important player in steroid hormone biosynthesis, catalysing the first and rate-limiting step, the side-chain cleavage of cholesterol to pregnenolone, which provides the precursor for all major steroid hormones. A resurrected ancestral isoform of CYP11A (CYP11A_N1) exhibits different substrate specificities to extant vertebrate CYP11A1 forms which implies an evolutionary change in structural features. Hence, we solved the structure of the resurrected ancestral CYP11A_N1 isoform and identified the major structural changes between ancestral and extant CYP11A isoforms that lead to different catalytic properties for cholesterol metabolism. Our work presents the first structure of an ancestral mitochondrial cytochrome P450 and highlights how structural changes shaped the evolution of steroid hormone biosynthesis.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"274 ","pages":"Article 113105"},"PeriodicalIF":3.2,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262809","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}
Pub Date : 2025-10-07DOI: 10.1016/j.jinorgbio.2025.113093
Robert B. Piel, III , Chibuike D. Obi , Martonio Ponte Viana , Mathilda M. Willoughby , Osiris Martinez-Guzman , Aaliyah Wadley , Yasaman Jami-Alahmadi , James A. Wohlschlegel , Kevin G. Hicks , Jared Rutter , J. Alan Maschek , J. Leon Catrow , James Cox , Amit R. Reddi , Oleh Khalimonchuk , Amy E. Medlock
Heme is a cofactor essential for a multitude of biological reactions. The terminal step of heme synthesis occurs in the mitochondrial matrix which means that heme must be trafficked from there to other locales in the cell. Thus, identifying intracellular heme chaperones is crucial to understanding regulation of global cellular metabolism. The heme-binding protein progesterone receptor membrane component 1 (PGRMC1) has been proposed to function as a chaperone for several biologically active molecules including heme, but its cellular role is not fully understood. Here, we investigate the function of PGRMC1 in heme metabolism. By monitoring intracellular heme location and concentrations in Saccharomyces cerevisiae, we show that mutants lacking damage associated protein 1 (Dap1), the yeast ortholog of PGRMC1, have altered nuclear heme trafficking which can be corrected by complementation with DAP1 or PGRMC1. Biochemical analyses reveal that PGRMC1 co-localizes with known mitochondrial-associated membrane (MAM) proteins and proteomic comparison of interaction partners shows enrichment of MAM-associated proteins and pathways. Metabolomics profiling of wild-type and PGRMC1 knockout cells identifies significant changes of several metabolites, including heme, several amino acids, long chain acyl-carnitine, ethanolamine phosphate, and mevalonic acid. Together, these results provide evidence that PGRMC1 is involved in heme trafficking and homeostasis through MAMs.
{"title":"Progesterone receptor membrane component 1 (PGRMC1) regulates Heme trafficking through mitochondria-ER junctions","authors":"Robert B. Piel, III , Chibuike D. Obi , Martonio Ponte Viana , Mathilda M. Willoughby , Osiris Martinez-Guzman , Aaliyah Wadley , Yasaman Jami-Alahmadi , James A. Wohlschlegel , Kevin G. Hicks , Jared Rutter , J. Alan Maschek , J. Leon Catrow , James Cox , Amit R. Reddi , Oleh Khalimonchuk , Amy E. Medlock","doi":"10.1016/j.jinorgbio.2025.113093","DOIUrl":"10.1016/j.jinorgbio.2025.113093","url":null,"abstract":"<div><div>Heme is a cofactor essential for a multitude of biological reactions. The terminal step of heme synthesis occurs in the mitochondrial matrix which means that heme must be trafficked from there to other locales in the cell. Thus, identifying intracellular heme chaperones is crucial to understanding regulation of global cellular metabolism. The heme-binding protein progesterone receptor membrane component 1 (PGRMC1) has been proposed to function as a chaperone for several biologically active molecules including heme, but its cellular role is not fully understood. Here, we investigate the function of PGRMC1 in heme metabolism. By monitoring intracellular heme location and concentrations in <em>Saccharomyces cerevisiae,</em> we show that mutants lacking damage associated protein 1 (Dap1), the yeast ortholog of PGRMC1, have altered nuclear heme trafficking which can be corrected by complementation with <em>DAP1</em> or <em>PGRMC1</em>. Biochemical analyses reveal that PGRMC1 co-localizes with known mitochondrial-associated membrane (MAM) proteins and proteomic comparison of interaction partners shows enrichment of MAM-associated proteins and pathways. Metabolomics profiling of wild-type and PGRMC1 knockout cells identifies significant changes of several metabolites, including heme, several amino acids, long chain acyl-carnitine, ethanolamine phosphate, and mevalonic acid. Together, these results provide evidence that PGRMC1 is involved in heme trafficking and homeostasis through MAMs.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113093"},"PeriodicalIF":3.2,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145353384","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号