Pub Date : 2025-05-02DOI: 10.1007/s00775-025-02115-y
Tabea Lenz, Uroš Javornik, Marian Hebenbrock, Janez Plavec, Jens Müller
The interaction of metal ions with nucleic acids was studied by determining the initial binding sites of Ag+ ions at unmodified B-DNA by NMR spectroscopy. In particular, NMR spectra were recorded of the Dickerson-Drew dodecamer sequence in the presence of different ratios of Ag+ ions to DNA. The data indicate that the coordination of the first three Ag+ ions per duplex preferentially takes place inside the B-DNA helix rather than at other possible binding sites such as the negatively charged phosphate backbone and/or the endocyclic N7 position of purine residues. Larger DNA aggregates are formed in the presence of excess Ag+ ions, as indicated by the formation of a precipitate and by significant changes in the circular dichroism spectra. As shown by a titration with chloride ions, the Ag+ ions are only loosely bound to the nucleic acids and can be released by precipitation of AgCl.
{"title":"Determination of silver(I)-binding sites in canonical B-DNA by NMR spectroscopy","authors":"Tabea Lenz, Uroš Javornik, Marian Hebenbrock, Janez Plavec, Jens Müller","doi":"10.1007/s00775-025-02115-y","DOIUrl":"10.1007/s00775-025-02115-y","url":null,"abstract":"<div><p>The interaction of metal ions with nucleic acids was studied by determining the initial binding sites of Ag<sup>+</sup> ions at unmodified B-DNA by NMR spectroscopy. In particular, NMR spectra were recorded of the Dickerson-Drew dodecamer sequence in the presence of different ratios of Ag<sup>+</sup> ions to DNA. The data indicate that the coordination of the first three Ag<sup>+</sup> ions per duplex preferentially takes place inside the B-DNA helix rather than at other possible binding sites such as the negatively charged phosphate backbone and/or the endocyclic N7 position of purine residues. Larger DNA aggregates are formed in the presence of excess Ag<sup>+</sup> ions, as indicated by the formation of a precipitate and by significant changes in the circular dichroism spectra. As shown by a titration with chloride ions, the Ag<sup>+</sup> ions are only loosely bound to the nucleic acids and can be released by precipitation of AgCl.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 4-5","pages":"381 - 395"},"PeriodicalIF":2.7,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12316801/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952776","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}
Pub Date : 2025-04-20DOI: 10.1007/s00775-025-02114-z
Marzieh Anjomshoa, Bagher Amirheidari, Mehdi Sahihi, Jan Janczak, Hamid Forootanfar, Alireza Farsinejad, Yasaman Abolhassani, Somayyeh Karami-Mohajeri
A new dimethyl-substituted bipyridine–Zn(II) complex (2Mebpy–Zn) was synthesized and structurally characterized. Single-crystalline structure of the complex was elucidated as [Zn(2Mebpy)3](ClO4)2∙1.5(dioxane) by X-ray diffraction, where 2Mebpy is 4,4′-dimethyl-2,2′-bipyridine. The three-dimensional electrostatic potential maps (3D ESP) were plotted for [Zn(2Mebpy)3]2+ cation and [Zn(2Mebpy)3](ClO4)2 molecule. In vitro cytotoxicity studies indicated significant cytotoxicity of 2Mebpy–Zn against both breast (MCF-7) and glioblastoma (U-87) cancer cells relative to normal murine embryo cells (NIH/3T3). The results are indicative of a superior selectivity toward MCF-7 over the other cell lines as confirmed by IC50 value of 5.1 ± 0.5 µM after 48 h. Interestingly, MCF-7 and U-87 cells death induced by 2Mebpy–Zn mostly proceed through an apoptotic pathway which probably associates with the overproduction of reactive oxygen species (ROS). The Zn(II) complex suppressed the metastatic affinity of MCF-7 cells by blocking migration as well as formation of colonies. Also, the expression of two opponent apoptosis-relevant genes (BAX and BCL2) measured by real-time polymerase chain reaction (qPCR) experiments indicated that 2Mebpy–Zn could potentially trigger apoptotic cell death. Moreover, 2Mebpy–Zn could cleave hydrolytically the pUC19 DNA without the need to add any external agent. Finally, the binding affinity of two enantiomers of 2Mebpy–Zn toward cancer therapeutic targets, such as anti-apoptotic proteins, estrogen receptor α, tubulin, and topoisomerase II, was studied by in silico molecular docking. In conclusion, 2Mebpy–Zn can be introduced as a potential therapeutic agent in breast cancer and indicates that other metal complexes with bipyridine derivatives can also exhibit promising anticancer effects.
{"title":"In vitro cellular and molecular plus in silico studies of a substituted bipyridine-coordinated Zn(II) ion: cytotoxicity, ROS-induced apoptosis, anti-metastasis, and BAX/BCL2 genes expression","authors":"Marzieh Anjomshoa, Bagher Amirheidari, Mehdi Sahihi, Jan Janczak, Hamid Forootanfar, Alireza Farsinejad, Yasaman Abolhassani, Somayyeh Karami-Mohajeri","doi":"10.1007/s00775-025-02114-z","DOIUrl":"10.1007/s00775-025-02114-z","url":null,"abstract":"<div><p>A new dimethyl-substituted bipyridine–Zn(II) complex (<sup><b>2Me</b></sup><b>bpy–Zn</b>) was synthesized and structurally characterized. Single-crystalline structure of the complex was elucidated as [Zn(<sup>2Me</sup>bpy)<sub>3</sub>](ClO<sub>4</sub>)<sub>2</sub>∙1.5(dioxane) by X-ray diffraction, where <sup>2Me</sup>bpy is 4,4′-dimethyl-2,2′-bipyridine. The three-dimensional electrostatic potential maps (3D ESP) were plotted for [Zn(<sup>2Me</sup>bpy)<sub>3</sub>]<sup>2+</sup> cation and [Zn(<sup>2Me</sup>bpy)<sub>3</sub>](ClO<sub>4</sub>)<sub>2</sub> molecule. In vitro cytotoxicity studies indicated significant cytotoxicity of <sup><b>2Me</b></sup><b>bpy–Zn</b> against both breast (MCF-7) and glioblastoma (U-87) cancer cells relative to normal murine embryo cells (NIH/3T3). The results are indicative of a superior selectivity toward MCF-7 over the other cell lines as confirmed by IC<sub>50</sub> value of 5.1 ± 0.5 <i>µ</i>M after 48 h. Interestingly, MCF-7 and U-87 cells death induced by <sup><b>2Me</b></sup><b>bpy–Zn</b> mostly proceed through an apoptotic pathway which probably associates with the overproduction of reactive oxygen species (ROS). The Zn(II) complex suppressed the metastatic affinity of MCF-7 cells by blocking migration as well as formation of colonies. Also, the expression of two opponent apoptosis-relevant genes (BAX and BCL2) measured by real-time polymerase chain reaction (qPCR) experiments indicated that <sup><b>2Me</b></sup><b>bpy–Zn</b> could potentially trigger apoptotic cell death. Moreover, <sup><b>2Me</b></sup><b>bpy–Zn</b> could cleave hydrolytically the pUC19 DNA without the need to add any external agent. Finally, the binding affinity of two enantiomers of <sup><b>2Me</b></sup><b>bpy–Zn</b> toward cancer therapeutic targets, such as anti-apoptotic proteins, estrogen receptor α, tubulin, and topoisomerase II, was studied by in silico molecular docking. In conclusion, <sup><b>2Me</b></sup><b>bpy–Zn</b> can be introduced as a potential therapeutic agent in breast cancer and indicates that other metal complexes with bipyridine derivatives can also exhibit promising anticancer effects.</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":"30 4-5","pages":"359 - 379"},"PeriodicalIF":2.7,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143954616","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}
Pub Date : 2025-03-24DOI: 10.1007/s00775-025-02113-0
Silvia Pizzanelli, Emanuela Pitzalis, Simone Botticelli, Fabrizio Machetti, Cecilia Faraloni, Giovanni La Penna
Unicellular algae can produce pure hydrogen gas from water and sun-light. We observed Chlorella vulgaris whole cells when they produce hydrogen using X-band continuous-wave electron spin resonance (ESR). Whole-cell spectroscopy is particularly useful in those cases where purified enzymes are sensitive to oxidant air conditions. By tuning cell preparation, the microwave power, the temperature, the time of air exposure, we could isolate from the background signal candidate markers of hydrogen production. Our observations indicate the presence of a species consistent mainly with an intermediate ({hbox {Fe}_{3}hbox {S}_{4}{^{+}}}) cluster when hydrogen production is high, but not maximal, and when FeS cluster oxidation has just begun. The optimal conditions to detect the above marker by ESR have been identified. Our investigation paves the way to extensive statistical analysis of cellular conditions in future studies using whole-cell ESR.
{"title":"Electron spin resonance in microalgae whole-cells to monitor hydrogen production","authors":"Silvia Pizzanelli, Emanuela Pitzalis, Simone Botticelli, Fabrizio Machetti, Cecilia Faraloni, Giovanni La Penna","doi":"10.1007/s00775-025-02113-0","DOIUrl":"10.1007/s00775-025-02113-0","url":null,"abstract":"<p>Unicellular algae can produce pure hydrogen gas from water and sun-light. We observed <i>Chlorella vulgaris</i> whole cells when they produce hydrogen using X-band continuous-wave electron spin resonance (ESR). Whole-cell spectroscopy is particularly useful in those cases where purified enzymes are sensitive to oxidant air conditions. By tuning cell preparation, the microwave power, the temperature, the time of air exposure, we could isolate from the background signal candidate markers of hydrogen production. Our observations indicate the presence of a species consistent mainly with an intermediate <span>({hbox {Fe}_{3}hbox {S}_{4}{^{+}}})</span> cluster when hydrogen production is high, but not maximal, and when FeS cluster oxidation has just begun. The optimal conditions to detect the above marker by ESR have been identified. Our investigation paves the way to extensive statistical analysis of cellular conditions in future studies using whole-cell ESR.</p>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 3","pages":"229 - 240"},"PeriodicalIF":2.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-025-02113-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143699463","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}
Pub Date : 2025-03-22DOI: 10.1007/s00775-025-02111-2
Karin Ben Zaken, Rivka Bouhnik, Naama Omer, Naamah Bloch, Abraham O. Samson
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by brain aggregates of amyloid-β (Aβ) plaques and Tau tangles. Despite extensive research, effective therapy for AD remains elusive. Polyoxometalates (POMs), a class of inorganic compounds with diverse chemical structures and properties, are emerging as potential candidates for AD treatment due to their ability to target key molecular players implicated in disease pathogenesis, such as Aβ, acetylcholinesterase (AChE) and butyryl acetylcholinesterase (BChE). Here, we use molecular docking to predict the binding pose and affinities of POMs to 10 top targets associated with AD. First, we validate our method by replicating experimentally known binding of POMs to Aβ (ΔG = – 9.67 kcal/mol), AChE (ΔG = – 9.39 kcal/mol) and BChE (ΔG = – 10.86 kcal/mol). Then, using this method, we show that POM can also bind β-secretase 1 (BACE1, ΔG = – 10.14 kcal/mol), presenilin 1 (PSEN1, ΔG = – 10.65 kcal/mol), presenilin 2 (PSEN2, ΔG = – 7.94 kcal/mol), Amyloid Precursor Protein (APP, ΔG = – 7.26 kcal/mol), Apolipoprotein E (APOE4, ΔG = – 10.05 kcal/mol), Microtubule-Associated Protein Tau (MAPT, ΔG = – 5.28 kcal/mol) depending on phosphorylation, and α-synuclein (SNCA, ΔG = – 7.64 kcal/mol). Through such binding, POMs offer the potential to mitigate APP cleavage, Aβ oligomer neurotoxicity, Aβ aggregation, thereby attenuating disease progression. Overall, our molecular docking study represents a powerful tool in the discovery of POM-based therapeutics for AD, facilitating the development of novel treatments for AD.
{"title":"Polyoxometalates bind multiple targets involved in Alzheimer’s disease","authors":"Karin Ben Zaken, Rivka Bouhnik, Naama Omer, Naamah Bloch, Abraham O. Samson","doi":"10.1007/s00775-025-02111-2","DOIUrl":"10.1007/s00775-025-02111-2","url":null,"abstract":"<div><p>Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by brain aggregates of amyloid-β (Aβ) plaques and Tau tangles. Despite extensive research, effective therapy for AD remains elusive. Polyoxometalates (POMs), a class of inorganic compounds with diverse chemical structures and properties, are emerging as potential candidates for AD treatment due to their ability to target key molecular players implicated in disease pathogenesis, such as Aβ, acetylcholinesterase (AChE) and butyryl acetylcholinesterase (BChE). Here, we use molecular docking to predict the binding pose and affinities of POMs to 10 top targets associated with AD. First, we validate our method by replicating experimentally known binding of POMs to Aβ (Δ<i>G</i> = – 9.67 kcal/mol), AChE (Δ<i>G</i> = – 9.39 kcal/mol) and BChE (Δ<i>G</i> = – 10.86 kcal/mol). Then, using this method, we show that POM can also bind β-secretase 1 (BACE1, Δ<i>G</i> = – 10.14 kcal/mol), presenilin 1 (PSEN1, Δ<i>G</i> = – 10.65 kcal/mol), presenilin 2 (PSEN2, Δ<i>G</i> = – 7.94 kcal/mol), Amyloid Precursor Protein (APP, Δ<i>G</i> = – 7.26 kcal/mol), Apolipoprotein E (APOE4, Δ<i>G</i> = – 10.05 kcal/mol), Microtubule-Associated Protein Tau (MAPT, Δ<i>G</i> = – 5.28 kcal/mol) depending on phosphorylation, and α-synuclein (SNCA, Δ<i>G</i> = – 7.64 kcal/mol). Through such binding, POMs offer the potential to mitigate APP cleavage, Aβ oligomer neurotoxicity, Aβ aggregation, thereby attenuating disease progression. Overall, our molecular docking study represents a powerful tool in the discovery of POM-based therapeutics for AD, facilitating the development of novel treatments for AD.</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":"30 3","pages":"299 - 309"},"PeriodicalIF":2.7,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-025-02111-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143690762","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}
Nano-iron oral supplements emerged as efficient supplements with reduced gastrointestinal side effects. Very recently, nanorods of β-FeOOH was introduced as the most efficient shape of nano-iron to be employed as oral supplement. Developed technologies in the fabrication of nanostructures provides the ability to synthesize β-FeOOH nanorods in various lengths while the other features are constant. As we all know, particles’ length has an immense impact on the biologic properties of nanorods. But there are no in vivo data about the impacts of particles length on the bioavailability and possible toxicity of β-FeOOH nanorods. So, in this study, different lengths of β-FeOOH nanorods were fabricated and employed as oral iron supplements. In this order, β-FeOOH nanorods with two lengths (mean length 50 nm and 100 nm) were successfully synthesized via hydrolysis reaction. Oral supplementation of Sprague–Dawley rats with the synthesized nanorods and FeSO4 was performed in two dosages, 10 and 20 mg/Kg. After 1-month daily treatment, blood and tissue samples were collected for hematologic, toxicologic, and pathologic analyses. Compared to FeSO4, β-FeOOH nanorods demonstrated greater efficiency to improve serum iron levels (~ threefold increase) and also hematological parameters. Similar to FeSO4, nanorods exhibited any adverse effect on liver and spleen tissues. With the same level of biocompatibility, short nanorods provided better bioavailability than the long nanorods. These data approved the short β-FeOOH nanorods as efficient and safe nanostructures to be employed in nano-based formulation of iron supplements.
{"title":"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/s00775-025-02110-3","DOIUrl":"10.1007/s00775-025-02110-3","url":null,"abstract":"<div><p>Nano-iron oral supplements emerged as efficient supplements with reduced gastrointestinal side effects. Very recently, nanorods of β-FeOOH was introduced as the most efficient shape of nano-iron to be employed as oral supplement. Developed technologies in the fabrication of nanostructures provides the ability to synthesize β-FeOOH nanorods in various lengths while the other features are constant. As we all know, particles’ length has an immense impact on the biologic properties of nanorods. But there are no in vivo data about the impacts of particles length on the bioavailability and possible toxicity of β-FeOOH nanorods. So, in this study, different lengths of β-FeOOH nanorods were fabricated and employed as oral iron supplements. In this order, β-FeOOH nanorods with two lengths (mean length 50 nm and 100 nm) were successfully synthesized via hydrolysis reaction. Oral supplementation of Sprague–Dawley rats with the synthesized nanorods and FeSO<sub>4</sub> was performed in two dosages, 10 and 20 mg/Kg. After 1-month daily treatment, blood and tissue samples were collected for hematologic, toxicologic, and pathologic analyses. Compared to FeSO<sub>4</sub>, β-FeOOH nanorods demonstrated greater efficiency to improve serum iron levels (~ threefold increase) and also hematological parameters. Similar to FeSO<sub>4</sub>, nanorods exhibited any adverse effect on liver and spleen tissues. With the same level of biocompatibility, short nanorods provided better bioavailability than the long nanorods. These data approved the short β-FeOOH nanorods as efficient and safe nanostructures to be employed in nano-based formulation of iron supplements.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 4-5","pages":"345 - 357"},"PeriodicalIF":2.7,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143668536","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}
Pub Date : 2025-03-13DOI: 10.1007/s00775-025-02109-w
Spenser Stone, Logan Peters, Charlotte Fricke, W. Keith Ray, Kylie D. Allen
A noncanonical route for p-aminobenzoate (pABA) biosynthesis in select bacteria utilizes a novel self-sacrificing heme oxygenase-like domain-containing oxidase/oxygenase (HDO) superfamily member. The recently characterized self-sacrificing pABA synthase from Chlamydia trachomatis (“CADD”) requires manganese and likely employs a heterobimetallic Mn/Fe cofactor. A conserved active site tyrosine residue is cleaved from the protein backbone to serve as the substrate for pABA synthesis and a lysine residue is the amino group donor. Here, we investigated the orthologous pABA synthase from the ammonia-oxidizing bacterium, Nitrosomonas europaea, which we refer to as NePabS. Consistent with the previously studied C. trachomatis enzyme, purified NePabS produces pABA in vitro in a reaction that only requires a metal cofactor, molecular oxygen, and a reducing agent, but no other substrates. Interestingly, maximal activity was observed with the addition of only iron as opposed to manganese and iron; thus, NePabS utilizes the more traditional Fe/Fe cofactor employed by most characterized HDO superfamily members. The self-sacrificing residues were confirmed to be Tyr25 and Lys159, which are the corresponding self-sacrificing residues in the CADD reaction. Strikingly, we could switch the metal dependence (Fe/Fe to Mn/Fe) and significantly improve the activity (~ twofold) of NePabS by substituting two phenylalanine residues with tyrosine residues (F148Y/F177Y), thus rendering the enzyme more similar to CADD. These results demonstrate that these two aromatic residues play an essential role in dictating metal specificity and potentially the proposed radical translocation process that facilitates the tyrosine cleavage reaction for pABA synthesis.
{"title":"Biochemical characterization of the self-sacrificing p-aminobenzoate synthase from Nitrosomonas europaea reveals key residues involved in selecting a Fe/Fe or Mn/Fe cofactor","authors":"Spenser Stone, Logan Peters, Charlotte Fricke, W. Keith Ray, Kylie D. Allen","doi":"10.1007/s00775-025-02109-w","DOIUrl":"10.1007/s00775-025-02109-w","url":null,"abstract":"<div><p>A noncanonical route for <i>p</i>-aminobenzoate (pABA) biosynthesis in select bacteria utilizes a novel self-sacrificing heme oxygenase-like domain-containing oxidase/oxygenase (HDO) superfamily member. The recently characterized self-sacrificing pABA synthase from <i>Chlamydia trachomatis</i> (“CADD”) requires manganese and likely employs a heterobimetallic Mn/Fe cofactor. A conserved active site tyrosine residue is cleaved from the protein backbone to serve as the substrate for pABA synthesis and a lysine residue is the amino group donor. Here, we investigated the orthologous pABA synthase from the ammonia-oxidizing bacterium, <i>Nitrosomonas europaea</i>, which we refer to as <i>Ne</i>PabS. Consistent with the previously studied <i>C. trachomatis</i> enzyme, purified <i>Ne</i>PabS produces pABA in vitro in a reaction that only requires a metal cofactor, molecular oxygen, and a reducing agent, but no other substrates. Interestingly, maximal activity was observed with the addition of only iron as opposed to manganese and iron; thus, <i>Ne</i>PabS utilizes the more traditional Fe/Fe cofactor employed by most characterized HDO superfamily members. The self-sacrificing residues were confirmed to be Tyr25 and Lys159, which are the corresponding self-sacrificing residues in the CADD reaction. Strikingly, we could switch the metal dependence (Fe/Fe to Mn/Fe) and significantly improve the activity (~ twofold) of <i>Ne</i>PabS by substituting two phenylalanine residues with tyrosine residues (F148Y/F177Y), thus rendering the enzyme more similar to CADD. These results demonstrate that these two aromatic residues play an essential role in dictating metal specificity and potentially the proposed radical translocation process that facilitates the tyrosine cleavage reaction for pABA synthesis.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 3","pages":"271 - 281"},"PeriodicalIF":2.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-025-02109-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623079","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}
Pub Date : 2025-03-13DOI: 10.1007/s00775-025-02106-z
Inês B. Trindade, Bruno M. Fonseca, Teresa Catarino, Pedro M. Matias, Elin Moe, Ricardo O. Louro
Shewanella are bacteria widespread in marine and brackish water environments and emergent opportunistic pathogens. Their environmental versatility depends on the ability to produce numerous iron-rich proteins, mainly multiheme c-type cytochromes. Although iron plays a vital role in the versatility of Shewanella species, very few studies exist regarding the strategies by which these bacteria scavenge iron from the environment. Siderophore-mediated iron transport is a commonly employed strategy for iron acquisition, and it was identified among Shewanella spp. over two decades ago. Shewanella species produce hydroxamate-type siderophores and iron removal from these compounds can occur in the cytoplasm via Fe(III)–siderophore reduction mediated by siderophore-interacting proteins (SIPs). The genome of Shewanella putrefaciens DSM 9451 isolated from an infected child contains representatives of the two different families of SIPs: the flavin-containing siderophore reductase (SbSIP) and the iron–sulfur cluster-containing ferric–siderophore reductase (SbFSR). Here, we report their expression, purification, and further biochemical characterization of SbSIP. The structural and functional characterization of SbSIP and comparison with the homologous SIP from Shewanella frigidimarina (SfSIP) revealed similarities between these proteins including a common binding pocket for NADH, NADPH, and siderophore substrates plus a pronounced redox-Bohr effect that ensures coupled transfer of electrons and protons in the physiological pH range. These mechanistic aspects open the door for further investigations on developing drugs that interfere with the iron metabolism of these bacteria and thereby prevent their spread.
{"title":"Flavin-containing siderophore-interacting protein of Shewanella putrefaciens DSM 9451 reveals common structural and functional aspects of ferric–siderophore reduction","authors":"Inês B. Trindade, Bruno M. Fonseca, Teresa Catarino, Pedro M. Matias, Elin Moe, Ricardo O. Louro","doi":"10.1007/s00775-025-02106-z","DOIUrl":"10.1007/s00775-025-02106-z","url":null,"abstract":"<div><p><i>Shewanella</i> are bacteria widespread in marine and brackish water environments and emergent opportunistic pathogens. Their environmental versatility depends on the ability to produce numerous iron-rich proteins, mainly multiheme <i>c</i>-type cytochromes. Although iron plays a vital role in the versatility of <i>Shewanella</i> species, very few studies exist regarding the strategies by which these bacteria scavenge iron from the environment. Siderophore-mediated iron transport is a commonly employed strategy for iron acquisition, and it was identified among <i>Shewanella</i> spp. over two decades ago. <i>Shewanella</i> species produce hydroxamate-type siderophores and iron removal from these compounds can occur in the cytoplasm via Fe(III)–siderophore reduction mediated by siderophore-interacting proteins (SIPs). The genome of <i>Shewanella putrefaciens</i> DSM 9451 isolated from an infected child contains representatives of the two different families of SIPs: the flavin-containing siderophore reductase (<i>Sb</i>SIP) and the iron–sulfur cluster-containing ferric–siderophore reductase (<i>Sb</i>FSR). Here, we report their expression, purification, and further biochemical characterization of <i>Sb</i>SIP. The structural and functional characterization of <i>Sb</i>SIP and comparison with the homologous SIP from <i>Shewanella frigidimarina</i> (<i>Sf</i>SIP) revealed similarities between these proteins including a common binding pocket for NADH, NADPH, and siderophore substrates plus a pronounced redox-Bohr effect that ensures coupled transfer of electrons and protons in the physiological pH range. These mechanistic aspects open the door for further investigations on developing drugs that interfere with the iron metabolism of these bacteria and thereby prevent their spread.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 3","pages":"241 - 255"},"PeriodicalIF":2.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-025-02106-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622918","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}
Pub Date : 2025-03-12DOI: 10.1007/s00775-025-02108-x
Federico Balgera, Muyideen Kolapo Tijani, Johan Wennerberg, Kristina E. M. Persson, Ebbe Nordlander, Ricardo J. Ferreira
{"title":"Author Correction: Evaluation of Au(III) complexes as Plasmodium falciparum aquaglyceroporin (PfAQP) inhibitors by in silico and in vitro methods","authors":"Federico Balgera, Muyideen Kolapo Tijani, Johan Wennerberg, Kristina E. M. Persson, Ebbe Nordlander, Ricardo J. Ferreira","doi":"10.1007/s00775-025-02108-x","DOIUrl":"10.1007/s00775-025-02108-x","url":null,"abstract":"","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 3","pages":"311 - 311"},"PeriodicalIF":2.7,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612889","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}
Pub Date : 2025-03-08DOI: 10.1007/s00775-025-02107-y
Maxim Gvozdev, Iveta Turomsha, Nikolai Osipovich, Galina Ksendzova, Alina Khodosovskaya, Anton Siomchen, Janusz M. Dąbrowski, Natalia Loginova
Schiff bases bearing a sterically hindered phenolic moiety and their Bi(III) complexes were synthesized and characterized by physicochemical, quantum chemical, and biological methods. The compounds were screened in vitro against bacterial and yeast strains. It was found that Bi(III) complexes demonstrate higher antimicrobial activity compared to the parent ligands as well as to the commonly used drug (De-Nol®). Moreover, the antibacterial activity of investigated compounds did not directly correlate with their hemolytic activity, indicating that the antimicrobial effect of Bi(III) complexes cannot be explained solely by their membranolytic properties. Spectrofluorometric studies of the interaction of the Bi(III) complexes with plasma proteins indicate their moderate to high affinity toward BSA and hemoglobin, which is crucial for the determination of their pharmacological profile as well as toxicity assessment. Additionally, molecular docking was performed to predict the possible interaction modes and binding energies of the tested compounds at the molecular level. The results obtained may provide the basis for the design and development of novel Bi(III)-based antimicrobial agents.
{"title":"Bismuth(III) complexes of Schiff bases derived from aliphatic amines: interaction with biomolecules and antimicrobial activity","authors":"Maxim Gvozdev, Iveta Turomsha, Nikolai Osipovich, Galina Ksendzova, Alina Khodosovskaya, Anton Siomchen, Janusz M. Dąbrowski, Natalia Loginova","doi":"10.1007/s00775-025-02107-y","DOIUrl":"10.1007/s00775-025-02107-y","url":null,"abstract":"<div><p>Schiff bases bearing a sterically hindered phenolic moiety and their Bi(III) complexes were synthesized and characterized by physicochemical, quantum chemical, and biological methods. The compounds were screened in vitro against bacterial and yeast strains. It was found that Bi(III) complexes demonstrate higher antimicrobial activity compared to the parent ligands as well as to the commonly used drug (De-Nol®). Moreover, the antibacterial activity of investigated compounds did not directly correlate with their hemolytic activity, indicating that the antimicrobial effect of Bi(III) complexes cannot be explained solely by their membranolytic properties. Spectrofluorometric studies of the interaction of the Bi(III) complexes with plasma proteins indicate their moderate to high affinity toward BSA and hemoglobin, which is crucial for the determination of their pharmacological profile as well as toxicity assessment. Additionally, molecular docking was performed to predict the possible interaction modes and binding energies of the tested compounds at the molecular level. The results obtained may provide the basis for the design and development of novel Bi(III)-based antimicrobial agents.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 3","pages":"257 - 269"},"PeriodicalIF":2.7,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582153","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}
Pub Date : 2025-03-07DOI: 10.1007/s00775-025-02103-2
Mst Luthfun Nesa, Suman K. Mandal, Christine Toelzer, Diana Humer, Peter C. E. Moody, Imre Berger, Oliver Spadiut, Emma L. Raven
Horseradish peroxidase (HRP), isolated from horseradish roots, is heavily glycosylated, making it difficult to crystallize. In this work, we produced recombinant HRP in E. coli and obtained an X-ray structure of the ferric enzyme at 1.63 Å resolution. The structure shows that the recombinant HRP contains four disulphide bonds and two calcium ions, which are highly conserved in class III peroxidase enzymes. The heme active site contains histidine residues at the proximal (His 170) and distal (His 42) positions, and an active site arginine (Arg 38). Surprisingly, an ethylene glycol molecule was identified in the active site, forming hydrogen bonds with His 42 and Arg 38 at the δ-heme edge. The high yields obtained from the recombinant expression system, and the successful crystallization of the enzyme pave the way for new structural studies in the future.
{"title":"Crystal structure of ferric recombinant horseradish peroxidase","authors":"Mst Luthfun Nesa, Suman K. Mandal, Christine Toelzer, Diana Humer, Peter C. E. Moody, Imre Berger, Oliver Spadiut, Emma L. Raven","doi":"10.1007/s00775-025-02103-2","DOIUrl":"10.1007/s00775-025-02103-2","url":null,"abstract":"<div><p>Horseradish peroxidase (HRP), isolated from horseradish roots, is heavily glycosylated, making it difficult to crystallize. In this work, we produced recombinant HRP in <i>E. coli</i> and obtained an X-ray structure of the ferric enzyme at 1.63 Å resolution. The structure shows that the recombinant HRP contains four disulphide bonds and two calcium ions, which are highly conserved in class III peroxidase enzymes. The heme active site contains histidine residues at the proximal (His 170) and distal (His 42) positions, and an active site arginine (Arg 38). Surprisingly, an ethylene glycol molecule was identified in the active site, forming hydrogen bonds with His 42 and Arg 38 at the δ-heme edge. The high yields obtained from the recombinant expression system, and the successful crystallization of the enzyme pave the way for new structural studies in the future.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"Journal of Biological Inorganic Chemistry","volume":"30 3","pages":"221 - 227"},"PeriodicalIF":2.7,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-025-02103-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571909","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}
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