Journal of Inorganic Biochemistry最新文献

{"title":"Expanding the scope of resonance Raman spectroscopy in hydrogenase research: New observable states and reporter vibrations","authors":"","doi":"10.1016/j.jinorgbio.2024.112741","DOIUrl":"10.1016/j.jinorgbio.2024.112741","url":null,"abstract":"<div><div>Oxygen-tolerant [NiFe] hydrogenases are valuable blueprints for the activation and evolution of molecular hydrogen under application-relevant conditions. Vibrational spectroscopic techniques play a key role in the investigation of these metalloenzymes. For instance, resonance Raman spectroscopy has been introduced as a site-selective approach for probing metal-ligand coordinates of the [NiFe] active site and FeS clusters. Despite its success, this approach is still challenged by a limited number of detectable active-site states – due to missing resonance enhancement or intrinsic light sensitivity – and difficulties in their assignment. Utilizing two oxygen-tolerant [NiFe] hydrogenases as model systems, we illustrate how these challenges can be met by extending excitation and detection wavelength regimes in resonance Raman spectroscopic studies. Specifically, we observe that this technique does not only probe low-frequency metal-ligand vibrations but also high-frequency intra-ligand modes of the diatomic CO/CN⁻ ligands at the active site of [NiFe] hydrogenases. These reporter vibrations are routinely probed by infrared absorption spectroscopy, so that direct comparison of spectra from both techniques allows an unambiguous assignment of states detected by resonance Raman spectroscopy. Moreover, we find that a previously undetected state featuring a bridging hydroxo ligand between Ni and Fe can be probed using higher excitation wavelengths, as photoconversion occurring at lower wavelengths is avoided. In summary, this study expands the applicability of resonance Raman spectroscopy to hydrogenases and other complex metalloenzymes by introducing new strategies for probing and assigning redox-structural states of the active site.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis, characterization and comparative biological activity of a novel set of Cu(II) complexes containing azole-based ligand frames","authors":"","doi":"10.1016/j.jinorgbio.2024.112736","DOIUrl":"10.1016/j.jinorgbio.2024.112736","url":null,"abstract":"<div><div>The synthesis and spectroscopic characterization of three complexes containing a substituted 2-(2-pyridyl)benzothiazole (PyBTh) group in the ligand frame are reported along with the comparative biological activity. The ligands have been substituted at the 6-position with either a methoxy (Py(<em>OMe</em>)BTh) or a methyl group (Py(<em>Me</em>)BTh). Reaction of Py(<em>OMe</em>)BTh with either CuCl₂ or Cu(NO₃)₂·2.5 H₂O yielded the monomeric [Cu(Py(<em>OMe</em>)BTh))₂(NO₃)]NO₃·1.5 MeOH, (<strong>1</strong>·1.5 MeOH) complex or the dimeric [Cu(Py(<em>OMe</em>)BTh)Cl₂]₂ (<strong>2</strong>), respectively, with the nuclearity of the complex dependent on the starting Cu(II) salt. Reaction between the methyl substituted ligand and Cu(NO₃)₂·2.5 H₂O resulted in the isolation of Cu(Py(<em>Me</em>)BTh)(NO₃)₂·0.5 THF (<strong>3</strong>·0.5 THF). Complexes <strong>1</strong>–<strong>3</strong> were fully characterized. Cyclic voltammetry measurements were performed on all three complexes as well as on [Cu(PyBTh)₂(H₂O)](BF₄)₂ (<strong>4</strong>), a compound previously reported by us which contains the unsubstituted 2-(2-pyridyl)benzothiazole ligand. The biological activity was studied and included concentration dependent DNA binding and cleavage, antibacterial activity, and cancer cell toxicity. All complexes exhibited DNA cleavage activity, however <strong>2</strong> and <strong>4</strong> were found to be the most potent. Mechanistic studies revealed that the nuclease activity is dependent on an oxidative mechanism reliant principally on O₂⁻. Antibacterial studies revealed complex <strong>4</strong> was more potent compared to <strong>1</strong>–<strong>3</strong>. Cancer cell toxicity studies were carried out on HeLa, PC-3, and MCF7 cells with <strong>1</strong>–<strong>4</strong>, Cu(QBTh)(NO₃)₂(H₂O) and Cu(PyBIm)₃(BF₄)₂. The differences in the observed toxicities suggests the importance of the ligand and its substituents in modulating cell death.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322293","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":"Mononuclear high-spin iron(III) phthalocyanines","authors":"","doi":"10.1016/j.jinorgbio.2024.112737","DOIUrl":"10.1016/j.jinorgbio.2024.112737","url":null,"abstract":"<div><div>2,9(or 10),16(or 17), 23(or 24)-Tetradecyloxycarbonylphthalocyaninatoiron, FeTDPc, and 2,3,9,10,16,17,23,24-octadecyloxycarbonylphthalocyaninatoiron, FeODPc, were synthesized and characterized. These compounds seem to be in trivalent iron high-spin state in solvents such as chloroform, dichloromethane, benzene, and chlorobenzene, although their counter anion could not be detected by elemental analyses. They react with strong bases such as pyridine and imidazoles to form their mono- and subsequently their di-base complexes with formation constant of &gt;10⁶ and &lt; 200 dm³ mol⁻¹, respectively, in dichloromethane at 20 °C. The resultant mono-adducts appear to be trivalent iron low-spin while the di-base adducts are bivalent iron low-spin state complexes. The addition of ca. 10–30 equivalent of tetrabutylammonium-chloride or -bromide (electrolyte) to the solution containing FeTDPc or FeODPc, causes their spin-state change from iron(III) high to low-spin state. In a solid power state, however, both FeTDPc and FeODPc exist as a mixture of high-spin iron(III)- and intermediate-spin iron(II) species. Strangely, when these compounds are dissolved in polystyrene, i.e. each molecules are isolated from each other, the signals originated from the iron(II) component disappear.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314594","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":"Polyoxometalates and their composites for antimicrobial applications: Advances, mechanisms and future prospects","authors":"","doi":"10.1016/j.jinorgbio.2024.112739","DOIUrl":"10.1016/j.jinorgbio.2024.112739","url":null,"abstract":"<div><p>The overuse of antibiotics can lead to the development of antibiotic-resistant bacteria, which can be even more difficult to treat and pose an even greater threat to public health. In order to address the issue of antibiotic-resistant bacteria, researchers currently are exploring alternative methods of sterilization that are both effective and sustainable. Polyoxometalates (POMs), as emerging transition metal oxide compounds, exhibit significant potential in various applications due to their remarkable tunable physical and chemical performance, especially in antibacterial fields. They constitute a diverse family of inorganic clusters, characterized by a wide array of composition, structures and charges. Presently, several studies indicated that POM-based composites have garnered extensive attention in the realms of the antibacterial field and may become promising materials for future medical applications. Moreover, this review will focus on exploring the antibacterial properties and mechanisms of different kinds of organic-inorganic hybrid POMs, POM-based composites, films and hydrogels with substantial bioactivity, while POM-based composites have the dual advantages of POMs and other materials. Additionally, the potential antimicrobial mechanisms have also been discussed, mainly encompassing cell wall/membrane disruption, intracellular material leakage, heightened intracellular reactive oxygen species (ROS) levels, and depletion of glutathione (GSH). These findings open up exciting possibilities for POMs as exemplary materials in the antibacterial arena and expand their prospective applications.</p></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243102","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":"Construction of artificial peroxidase based on myoglobin scaffold for efficient degradation of meloxicam","authors":"","doi":"10.1016/j.jinorgbio.2024.112733","DOIUrl":"10.1016/j.jinorgbio.2024.112733","url":null,"abstract":"<div><p>A novel artificial peroxidase has been developed for the efficient degradation of the non-steroidal anti-inflammatory drug meloxicam by combining computer simulation and genetic engineering techniques. The results showed that the artificial peroxidase was able to completely degrade meloxicam within 90 s, with a degradation rate of 100 %, which was much higher than that of natural lacquer (46 %). The reaction time of the artificial enzyme was significantly shorter than that of natural peroxidase (10 min) and laccase (48 h). Further studies showed that the amino acid arrangement of the active site of the protein plays an important role in the catalytic performance. The degradation pathway of meloxicam was revealed using UPLC-MS analysis. In vitro toxicity assay showed complete disappearance of toxicity after meloxicam degradation. Therefore, the biocatalytic system proved to be an effective route for the green degradation of meloxicam with important application potential.</p></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243103","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":"In(III) pyridinecarboxylate complexes: Composition, solution equilibria estimation, bioevaluation and interactions with HSA","authors":"","doi":"10.1016/j.jinorgbio.2024.112738","DOIUrl":"10.1016/j.jinorgbio.2024.112738","url":null,"abstract":"<div><p>Two In(III) – pyridinecarboxylates ([In(Pic)₂(NO₃)(H₂O)] (InPic; HPic = picolinic acid), [In(HDpic)(Dpic)(H₂O)₂]·5H₂O (InDpic; H₂Dpic = dipicolinic acid), have been synthesized by one-step procedure. The complexes composition was confirmed by physicochemical analyses and X-ray diffraction confirmed molecular structure of both complexes. Moreover, complex species speciation was described in both systems by potentiometry and ¹H NMR spectroscopy and mononuclear complex species were determined; [In(Pic)]²⁺ (log<em>β</em>_<em>011</em> = 6.94(4)), [In(Pic)₂]⁺ (log<em>β</em>_<em>021</em> = 11.98(9)), [In(Dpic)]⁺ (log<em>β</em>_<em>011</em> = 10.42(6)), [In(Dpic)₂]⁻ (log<em>β</em>_<em>021</em> = 17.58(7)) and [In(Dpic)₂(OH)]²⁻ (log<em>β</em>_<em>−</em>_<em>121</em> = 10.18(6)). To confirm the complexes stability in 1 % DMSO, ¹H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial and anticancer assays indicate a more significant sensitivity of <em>S. aureus</em> bacteria and MDA-MB-231 cancer cells to the InPic complex (IC₅₀ = 25 and 340.7 μM) than to the InDpic (IC₅₀ = 50 and 975.4 μM). The interaction and binding mechanism of picolinic/dipicolinic acid and their indium(III) complexes with HSA (human serum albumin) were studied using fluorescence and CD spectroscopy. The results confirmed that the studied compounds had bound successfully to HSA, and the binding parameters and constants (<em>K</em>_<em>SV</em>, <em>K</em>_<em>q</em>, <em>K</em>_<em>b</em>) were calculated together with the number of binding sites. The binding forces were identified based on calculated thermodynamic parameters (<em>ΔG, ΔH, ΔS</em>). Synchronous spectra were used to study the microenvironment of Tyr and Trp residues and displacement assays revealed that site I was the preferred binding site. After binding, conformational changes were found to have occurred in the HSA molecule and the % α-helical content had decreased.</p></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243100","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":"In the search for new gold metalloantibiotics: In vitro evaluation of Au(III) (C^S)-cyclometallated complexes","authors":"","doi":"10.1016/j.jinorgbio.2024.112735","DOIUrl":"10.1016/j.jinorgbio.2024.112735","url":null,"abstract":"<div><p>A series of (C^S)-cyclometallated Au(III) cationic complexes of general formula [Au(dppta)(dtc)]⁺, [Au(dppta)(azmtd)]⁺ and [Au(dppta)(azc)Cl]⁺ (dppta = N,N-diisopropyl-<em>P</em>,<em>P</em>-diphenylphosphinothioic amide-κ²C,S; dtc = dithiocarbamate-κ²S,S′; azc = azolium-2-dithiocarboxylate-κ¹S; azmdt = azol(<em>in</em>)ium-2-(methoxy)methanedithiol-κ²S,S′) were synthetized and tested against a panel of bacterial strains belonging to different Gram-positive and Gram-negative species of the ESKAPE group of pathogens. Among the tested compounds, complex <strong>4c</strong> had the higher Therapeutic Index (TI) against multidrug resistant strains of <em>S. aureus</em>, <em>S. epidermidis</em> and <em>A. baumannii</em>, showing a more favourable cytotoxicity profile than the reference gold metalloantibiotic Auranofin.</p><p>© 2024 xxxxxxxx. Hosting by Elsevier B.V. All rights reserved.</p></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0162013424002599/pdfft?md5=6a2820dc9d1d49c64fbf07f7777892bd&pid=1-s2.0-S0162013424002599-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and functional mechanisms of cytochrome c oxidase","authors":"","doi":"10.1016/j.jinorgbio.2024.112730","DOIUrl":"10.1016/j.jinorgbio.2024.112730","url":null,"abstract":"<div><p>Cytochrome <em>c</em> oxidase (C<em>c</em>O) is the terminal enzyme in the electron transfer chain in mitochondria. It catalyzes the four-electron reduction of O₂ to H₂O and harnesses the redox energy to drive unidirectional proton translocation against a proton electrochemical gradient. A great deal of research has been conducted to comprehend the molecular properties of C<em>c</em>O. However, the mechanism by which the oxygen reduction reaction is coupled to proton translocation remains poorly understood. Here, we review the chemical properties of a variety of key oxygen intermediates of bovine C<em>c</em>O (bC<em>c</em>O) revealed by time-resolved resonance Raman spectroscopy and the structural features of the enzyme uncovered by serial femtosecond crystallography, an innovative technique that allows structural determination at room temperature without radiation damage. The implications of these data on the proton translocation mechanism are discussed.</p></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173831","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":"Thermodynamic and kinetic study of palladium(II) complexation with 1-methyl-2-mercaptoimidazole (methimazole) and their importance for structural design of metallodrugs","authors":"","doi":"10.1016/j.jinorgbio.2024.112722","DOIUrl":"10.1016/j.jinorgbio.2024.112722","url":null,"abstract":"<div><div>The acidobasic and complexing properties of 1-methyl-2-mercaptoimidazole (<em>Methimazole</em>, an anti-thyroid drug) were investigated. The p<em>K</em>_a 11.49 ± 0.03 was estimated by molecular absorption spectroscopy (<em>I</em> = 0.10 M NaCl, <em>t</em> = 25.0 ± 0.1 °C). This value is in good agreement with the value 11.58 ± 0.05, obtained using the solvent-extraction technique. Theoretical (LFER and quantum chemical calculations) and experimental (¹H/¹³C NMR spectroscopy) methods confirmed that the ligand prefers to be in the thion form, and the proton dissociation takes place on the nitrogen atom. Using glass electrode potentiometry, the complexation of the Pd(II) ion by the <em>methimazole</em> ligand occurs without the participation of protons. The best chemical model considers the [Pd(HL)]²⁺, [Pd(HL)₂]²⁺ and [Pd(HL)₃]²⁺ complex species, whose stability constants were also determined using spectroscopy and capillary zone electrophoretic (CZE) measurements. The metal complexes dissociate at –log [H⁺] &gt; 7, where an uncharged palladium(II) hydroxide is formed. The formation kinetics of the palladium(II) complex with <em>methimazole</em> were studied in perchloric and hydrochloric acids (<em>I</em> = 1.00 M, <em>t</em> = 15–40 °C) and the determined rate constants and activation parameters are consistent with literature values determined for the reactions of the Pd(II) ion with thiourea derivatives. The rate constants decrease by two orders of magnitude in both media, which can be assigned to a lower tendency of the chloride ion to dissociate from the [PdCl₄]²⁻ complex species than the water molecule from the [Pd(H₂O)₄]²⁺ ion. The presented results can be utilized for the design of new Pd and Pt metallodrugs.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320356","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":"Bio-molecular Fe(III) and Zn(II) complexes stimulate the interplay between PI3K/AKT1/EGFR inhibition and induce autophagy and apoptosis in epidermal skin cell cancer","authors":"","doi":"10.1016/j.jinorgbio.2024.112720","DOIUrl":"10.1016/j.jinorgbio.2024.112720","url":null,"abstract":"<div><p>This study investigated the effectiveness and safety of a hybrid thiosemicarbazone ligand (HL) and its metal complexes (Mn^II-L, Fe^III-L, Ni^II-HL, and Zn^II-HL) against epidermoid carcinoma (A-431). The results indicated that Fe^III-L is the most effective, with a high selectivity index of 8.01 and an IC₅₀ of 17.49 ± 2.12 μM for Fe^III-L. The study also revealed that the synthesized complexes effectively inhibited gene expression of the Phosphoinositide 3-kinases (PI3K), alpha serine/threonine-protein kinase (AKT1), epidermal growth factor receptor (EGFR2) axis mechanism (<em>P</em> &lt; 0.0001). Additionally, these complexes trigger a chain of events that include the inhibition of proliferating cell nuclear antigen (PCNA), transforming growth factor β1 (TGF β1), and topoisomerase II, and leading to a decrease in epidermoid cell proliferation. Furthermore, the inhibitory activity also resulted in the upregulation of caspases 3 and 9, indicating the acceleration of apoptotic markers, and the down regulation of miRNA221, suggesting a decrease in epidermoid proliferation. Molecular modeling of Fe^III-L revealed that it had the best binding energy −8.02 kcal/mol and interacted with five hydrophobic π-interactions with Val270, Gln79, Leu210, and Trp80 against AKT1. Furthermore, the binding orientation of Fe^III-L with Topoisomerase II was found to be the most stable, with a binding energy −8.25 kcal/mol. This stability was attributed to the presence of five hydrophobic π-interactions with His759, Guanin13, Cytosin8, and Ala465, and numerous ionic interactions, which were more favorable than those of doxorubicin and etoposide for new regimens of chemotherapeutic activities against skin cancer.</p></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144763","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}