Journal of Inorganic Biochemistry最新文献

{"title":"Corrigendum to “Positively charged residues play a significant role in enhancing the antibacterial activity of calcitermin” [Journal of Inorganic Biochemistry, 262 (2025), 112761]","authors":"Silvia Leveraro , Maria D'Accolti , Erika Marzola , Elisabetta Caselli , Remo Guerrini , Magdalena Rowinska-Zyrek , Maurizio Remelli , Denise Bellotti","doi":"10.1016/j.jinorgbio.2025.112940","DOIUrl":"10.1016/j.jinorgbio.2025.112940","url":null,"abstract":"","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"269 ","pages":"Article 112940"},"PeriodicalIF":3.8,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143959820","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":"Novel organoruthenium complexes containing β-Diketonates: Synthesis, characterization, DNA/HSA interactions, and the impact of biocompatible ionic liquids on biological activities","authors":"Nenad Janković ,&nbsp;Goran A. Bogdanović ,&nbsp;Nevenka Gligorijević ,&nbsp;Lazar Milović ,&nbsp;Milica Međedović ,&nbsp;Jovana Matić ,&nbsp;Marijana Kosanić ,&nbsp;Milan Vraneš ,&nbsp;Ana Rilak Simović","doi":"10.1016/j.jinorgbio.2025.112941","DOIUrl":"10.1016/j.jinorgbio.2025.112941","url":null,"abstract":"<div><div>In order to discover new dual-active agents, novel ruthenium (η⁶-<em>p-</em>cymene) complexes of the general formula [(η⁶-<em>p</em>-cym)Ru(<em>O<img>O</em>)Cl] with <em>O,O</em>-diketo ester ligands ethyl 2-hydroxy-4-aryl-4-oxobut-2-enoate (<strong>1–3</strong>), were synthesized. The complexes <strong>1–3</strong> were characterized by spectral techniques (UV–Vis, IR, ¹H and ¹³C NMR, and ESI-HRMS), elemental analysis, and X-ray crystallography. Based on <em>in vitro</em> DNA/HSA experiments, complex <strong>1</strong> exhibited the highest DNA/HSA-activity, suggesting that the presence of an alkene chain contributes to increased activity. The cytotoxic activity of <strong>1</strong>–<strong>3</strong> was evaluated in a panel of human cancer cell lines (A549, MDA-MB-231, LS-174, HeLa), and in one normal cell line (MRC-5), both in the absence and presence of biocompatible ionic liquids (BIO-ILs) such as cholinium glycinate (Cho-Gly), cholinium β-alaninate (Cho-Ala), and cholinium glutamate (Cho-Glu). Complex <strong>1</strong> exhibited the highest cytotoxicity and demonstrated selectivity toward HeLa cells. Additionally, its cytotoxicity was enhanced when combined with the BIO-ILs Cho-Gly and Cho-Ala. This study suggests that ionic liquids can influence the efficacy and selectivity of cancer treatments, highlighting the potential for enhancing therapeutic outcomes. However, it also emphasizes the need for a deeper understanding of BIO-IL interactions with cellular processes. Furthermore, compound <strong>1</strong> displayed strong antimicrobial activity against <em>Staphylococcus aureus</em> and <em>Escherichia coli</em> (MIC = 0.078 mg/mL). Among the assessed species, <em>Candida albicans</em> showed the highest sensitivity to antifungal activity. These results suggest that investigated compounds may have potential for further development as clinical candidates, pending additional studies.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112941"},"PeriodicalIF":3.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918464","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":"Synthesis, structure, stability, lipophilicity and insulin-sensitizing activity of new heteroleptic oxidovanadium(V) complexes","authors":"Sazida Yasmin Sultana ,&nbsp;Mitu Sharma ,&nbsp;Hiya Talukdar ,&nbsp;Gangutri Saikia ,&nbsp;Tahshina Begum ,&nbsp;Archana Sinha ,&nbsp;Subrata Mishra ,&nbsp;Bipul Sarma ,&nbsp;Suman Dasgupta ,&nbsp;Nashreen S. Islam","doi":"10.1016/j.jinorgbio.2025.112939","DOIUrl":"10.1016/j.jinorgbio.2025.112939","url":null,"abstract":"<div><div>A series of mixed-ligand oxidovanadium(V) complexes of the type, [VO₂(L) (N-N)] (<strong>1</strong>–<strong>4</strong>) featuring hydroxypyrones (L: maltol or ethyl-maltol) and (N-N): diimine [2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen)] ligands, are reported. The synthesized complexes were characterized by spectroscopic and analytical techniques (FTIR, UV–Vis, ⁵¹V NMR, HRMS, ICP-OES and TGA). Single crystal X-ray crystallography revealed the O₄N₂ ligand sphere to define a distorted octahedral coordination geometry in each case. Each of the complexes is stable in air in the solid state and have good solubility in water as well as in organic solvents. The partition co-efficient, log <em>P</em> (octanol-water) values for the complexes being in the range (0.72–1.12) indicated their lipophilic nature. The complexes <strong>1</strong>–<strong>4</strong>, along with two previously reported complexes [VO₂(deferiprone)(bpy)]·H₂O (<strong>5</strong>) and [VO₂(deferiprone)(phen)]·4H₂O (<strong>6</strong>) were examined for their <em>in vitro</em> insulin-sensitizing and insulin-like activities against insulin responsive L6 myoblast cells. The complex, [VO₂(Emal)(bpy)]₂·H₂O (<strong>3</strong>) exhibited the most pronounced insulin-sensitizing effect, which is comparable to that of the reference compound bis(maltolato)oxidovanadium(IV), BMOV. The <em>in vitro</em> cytotoxicity assay against the L6 myoblast cells showed that the compounds were less toxic compared to BMOV. The complexes <strong>1</strong>–<strong>6</strong> were screened for their <em>in vitro</em> inhibitory effect on the model enzyme wheat thylakoid acid phosphatase (ACP). The enzyme kinetic analysis revealed that, compounds induce their inhibitory effect <em>via</em> distinct pathways. The complexes <strong>1</strong>–<strong>4</strong> served as mixed type of inhibitor (<em>K</em>_ii &gt; <em>K</em>_i), whereas <strong>5</strong> and <strong>6</strong> served as classical non-competitive inhibitors of the enzyme (<em>K</em>_ii ≈ <em>K</em>_i).</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112939"},"PeriodicalIF":3.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927985","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":"Harnessing redox reactions for anticancer effects: A copper(II) Schiff base complex induces apoptosis in HepG2 liver cancer cells via ROS generation","authors":"Daniela Ganci ,&nbsp;Luisa D'Anna ,&nbsp;Giulia Abruscato ,&nbsp;Malo Le Chevalier ,&nbsp;Océane Quideau ,&nbsp;Salvatore Cataldo ,&nbsp;Alberto Pettignano ,&nbsp;Simona Rubino ,&nbsp;Roberto Chiarelli ,&nbsp;Giampaolo Barone ,&nbsp;Claudio Luparello ,&nbsp;Riccardo Bonsignore","doi":"10.1016/j.jinorgbio.2025.112938","DOIUrl":"10.1016/j.jinorgbio.2025.112938","url":null,"abstract":"<div><div>This study uncovers the potential of a copper(II) Schiff base complex, CuL²⁺, to access the Cu(I) oxidation state and generate reactive oxygen species (ROS), highlighting its significance in eventual therapeutic applications. UV–vis absorption spectroscopy was used to follow the redox stability of the metal complex, also in the presence of reducing agents, such as ascorbic acid and glutathione, and of the copper(I) chelator, bathocuproine disulfonate. Utilizing human tumor cell lines HepG2 (hepatocarcinoma cells), we assessed its efficacy in reducing cell viability, increasing the sub-G₀/G₁ cell fraction, and initiating apoptotic pathways. Cell viability assays demonstrated a dose-dependent cytotoxicity with pronounced effects at sub-micromolar concentrations. Flow cytometry revealed significant ROS production, followed by mitochondrial membrane potential dissipation, and caspase activation, underscoring CuL²⁺’s mechanism of action. These findings position CuL²⁺ as a promising candidate for cancer therapy, providing insights into copper complexes' therapeutic application through oxidative stress and apoptosis modulation.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112938"},"PeriodicalIF":3.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924920","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":"NRVS of FeS cluster proteins & models – A bestiary of nifty normal modes","authors":"Hongxin Wang ,&nbsp;Vladimir Pelmenschikov ,&nbsp;Yoshitaka Yoda ,&nbsp;Stephen P. Cramer","doi":"10.1016/j.jinorgbio.2025.112935","DOIUrl":"10.1016/j.jinorgbio.2025.112935","url":null,"abstract":"<div><div>Iron‑sulfur clusters are the primordial prosthetic groups for living systems, and they have even been proposed as partly responsible for the origin of life. They play a role in essential biological processes such as electron transfer, enzyme catalysis, DNA replication and repair, small molecule sensing, iron homeostasis, apoptosis, and human health and disease. They have frequently been studied by resonance Raman, electron paramagnetic resonance, and Mössbauer spectroscopies. Over the past two decades, we have used a synchrotron method called <strong>N</strong>uclear <strong>R</strong>esonance <strong>V</strong>ibrational <strong>S</strong>pectroscopy (NRVS) to examine the vibrational dynamics of a wide variety of Fe<img>S clusters in model systems and native proteins, ranging in complexity from single Fe sites in small rubredoxins to the [7Fe-9S-C-Mo-R-homocitrate] cluster in nitrogenases.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112935"},"PeriodicalIF":3.8,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134608","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":"Structure-function relationships in solvatochromic fluorophores targeting human and bovine carbonic anhydrases","authors":"Alyssa R. Malto ,&nbsp;Radhika Mehta ,&nbsp;Abigail Hinojosa,&nbsp;Dominique Tan,&nbsp;Alex L. Rerick,&nbsp;M. Haziq Qureshi,&nbsp;Meredith K. Purchal,&nbsp;Emily L. Que","doi":"10.1016/j.jinorgbio.2025.112934","DOIUrl":"10.1016/j.jinorgbio.2025.112934","url":null,"abstract":"<div><div>The development of reversible, selective, small molecule fluorescent probes displaying high fluorescence turn-on responses and tight binding affinity with specific metalloenzymes requires consideration of multiple factors. In this study, we report a library of fluorescent probes for two carbonic anhydrases: human carbonic anhydrase II (hCAII) and bovine carbonic anhydrase II (bCAII) and compare differences in fluorescence turn-on and binding affinity with molecular docking to gain insight into structure-function relationships. We analyze the roles of electrostatics, hydrophobics, and sterics in influencing the fluorescence response of the probes with hCAII and bCAII which have 80 % sequence identity but drastically different fluorescence turn-on values with amino(<em>na</em>)phthalimide-based fluorophores.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112934"},"PeriodicalIF":3.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890661","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":"Silver(I), Zinc(II) and Gallium(III) thiophene-2-carboxylates: Synthesis, solution and solid state characterization and bioevaluation","authors":"Michaela Rendošová ,&nbsp;Gabriela Kuzderová ,&nbsp;Róbert Gyepes ,&nbsp;Martin Kello ,&nbsp;Petra Olejníková ,&nbsp;Mária Vilková ,&nbsp;Sofia Gama ,&nbsp;Henrieta Matajová ,&nbsp;Mária Kožurková ,&nbsp;Alan Liška ,&nbsp;Simona Žiláková ,&nbsp;Zuzana Vargová","doi":"10.1016/j.jinorgbio.2025.112936","DOIUrl":"10.1016/j.jinorgbio.2025.112936","url":null,"abstract":"<div><div>Three 2-thiophenecarboxylate (<em>Tio2c</em>) complexes with different central atoms Ag(I), Zn(II) and Ga(III), <em>[Ag(Tio2c)]</em>_<em>2</em> (AgTio2c), <em>{[Zn</em>_<em>2</em><em>(Tio2c)</em>_<em>4</em><em>]</em>_<em>2</em><em>}</em>_<em>n</em> (ZnTio2c) and <em>[Ga(Tio2c)</em>_<em>3</em><em>]·H</em>_<em>2</em><em>O</em> (GaTio2c)<em>,</em> were synthesized and elemental, spectral and thermal analyses were used for their characterization. The AgTio2c and ZnTio2c single crystal structures confirmed the most common bidentate bridging coordination mode with typical strong argentophilic interactions in the case of AgTio2c complex. Complexes' stability in biological test stock solution were confirmed by ¹H NMR spectroscopy. Potentiometric data analysis by BSTAC program resulted in the determination of the stability constants of four complex species, [Zn(Tio2c)]⁺ (log <em>β</em>₁₁₀ = 2.06 ± 0.04), [Zn(Tio2c)(OH)] (log <em>β</em>₁₁_–₁ = −5.0 ± 0.1), [Zn(Tio2c)(OH)₂]⁻ (log <em>β</em>₁₁_–₂ = −12.9 ± 0.4) and [Zn(Tio2c)₂(OH)₂]²⁻ (log <em>β</em>₁₂_–₂ = −8.54 ± 0.04) with low abundance in aqueous solution. Theoretical estimation of the complex species in aqueous solution indicates a rather monodentate <em>Tio2c</em> coordination mode in the [Zn(Tio2c)]⁺ species, while the hydroxido complex species prefer a rather bidentate <em>O,Oʼ</em>-bond of the carboxylate. Antimicrobial and anticancer bioassays clearly confirmed the highest biological activity (toxicity) of the AgTio2c complex. The activity of ZnTio2c was slightly higher (or the same) compared to GaTio2c. The HSA (human serum albumin) binding behaviour of the AgTio2c, ZnTio2c and GaTio2c complexes was investigated using fluorescence spectroscopy and results revealed that the calculated <em>K</em>_<em>b</em> values were in the order of 10⁴ M⁻¹.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112936"},"PeriodicalIF":3.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898677","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":"Heterobimetallic ferrocenyl-chromone compounds as selective inhibitors of amyloid aggregation","authors":"Sara La Manna ,&nbsp;Valeria Panzetta ,&nbsp;Sossio Fabio Graziano ,&nbsp;Irene Cipollone ,&nbsp;Iogann Tolbatov ,&nbsp;Alessandro Marrone ,&nbsp;Maria Monti ,&nbsp;Paolo Antonio Netti ,&nbsp;Antonello Merlino ,&nbsp;Konrad Kowalski ,&nbsp;Daniela Marasco","doi":"10.1016/j.jinorgbio.2025.112932","DOIUrl":"10.1016/j.jinorgbio.2025.112932","url":null,"abstract":"<div><div>Amyloid aggregation is a key process in neurodegeneration, producing toxic species that contribute to disease progression. This underscores the urgent need to identify novel agents capable of reducing toxicity by modulating this aggregation process. Two heterobimetallic complexes incorporating a ferrocenyl-chromone (Fc-Chr) core were investigated: one featuring an additional gold(I) triphenylphosphine moiety, Fc-Chr-AuP(Ph)₃, and the other containing a dicobalt hexacarbonyl-alkyne unit, Fc-Chr-Co₂(CO)₆.</div><div>Their effects were evaluated toward on the aggregation of two amyloid models: the peptide spanning residues 264–277 of nucleophosmin 1 (NPM1₂₆₄_–₂₇₇) and the C-terminal fragment of the amyloid-β peptide (Aβ₂₁_–₄₀) each with unique primary sequences, self-aggregation mechanisms and kinetics. Thioflavin T- assays allowed to assess the impact of the metal complexes on the aggregation of two amyloids. Results indicate that the two complexes inhibit the early stages of the aggregation of peptides in a dose-dependent manner and a greater effect on NPM1₂₆₄_–₂₇₇ when compared to Aβ₂₁_–₄₀ was observed. Native electrospray ionization mass spectrometry revealed the formation of peculiar metal/peptide adducts in dependence on different metal-units in the complexes. Scanning electron microscopy (SEM) and density function theory (DFT) were also employed to further characterize the interaction between the metal compounds and the investigated peptides, while preliminary cell viability assays in SH-SY5Y cells supported inhibitory effects on the aggregation and showed reduction of amyloid cytotoxicity. Fc-Chr-Co₂(CO)₆ demonstrated the highest efficacy in modulating peptide aggregation, exerting a more significant impact on NMP1₂₆₄_–₂₇₇ relative to Aβ₂₁₋₄₀. These results support the use of ferrocenyl-chromone containing metal complexes as modulators of amyloid peptide aggregation.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112932"},"PeriodicalIF":3.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874223","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":"Selective isotope labeling probes the chemical capacity and reaction mechanism of a heterobimetallic Mn/Fe protein","authors":"Yunqiao J. Gan ,&nbsp;Joseph M. Hazel ,&nbsp;Brian C. Searle ,&nbsp;Hannah S. Shafaat","doi":"10.1016/j.jinorgbio.2025.112933","DOIUrl":"10.1016/j.jinorgbio.2025.112933","url":null,"abstract":"<div><div>The R2-like ligand binding oxidase (R2lox) forms a novel tyrosine-valine crosslink upon O₂ activation, reflecting an overall two-electron oxidation reaction. However, the mechanism through which the crosslink is formed is under debate, as the reaction can be initiated through either tyrosine O<img>H or valine C<img>H bond activation. Here, we utilized selective isotopic labeling and several spectroscopic techniques to probe the mechanism of this oxidation process. The results suggest that R2lox is capable of performing C<img>H bond activation, with both solvent and C<img>H kinetic isotope effects of approximately 2. Signatures of a high-valent Mn^IV/Fe^IV intermediate were observed through rapid-freeze-quench EPR that resemble an analogous intermediate found in the heterobimetallic radical-initiating enzyme, class Ic ribonucleotide reductase. This study provides a lower bound on the free energies of C<img>H bonds that can be cleaved by Mn/Fe cofactors and suggests the potential for such enzymes to functionally replace Fe/Fe cofactors in a range of reactions.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112933"},"PeriodicalIF":3.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948698","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":"Lanthanide(III)-dependent hydration of the methanol dehydrogenase cofactor, pyrroloquinoline quinone","authors":"Camille Blanc ,&nbsp;Lauriane Oriol ,&nbsp;Thayalan Rajeshkumar ,&nbsp;Christian Bijani ,&nbsp;Charles-Louis Serpentini ,&nbsp;Nicolas Giraud ,&nbsp;Laurent Maron ,&nbsp;Christelle Hureau ,&nbsp;Emilie Mathieu","doi":"10.1016/j.jinorgbio.2025.112924","DOIUrl":"10.1016/j.jinorgbio.2025.112924","url":null,"abstract":"<div><div>The mechanism by which pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenases (MDH), bearing either a Ca²⁺ or a lanthanide (Ln³⁺⁾ ion in their active site, oxidize methanol has been intensely debated. In particular, the Ln³⁺-dependent activity of Ln-MDH remains poorly understood. The lack of experimental evidence represents a significant limitation to improve our understanding of these enzymes. In this work, we propose that insights on Ca- and Ln-MDH reactivity can be gained by examining a model reaction, the hydration of PQQ. Indeed, this reaction is similar to the first step of the putative methanol addition-elimination mechanism and is expected to be similarly influenced by the metal ion. The apparent affinity constants of PQQ for Ca²⁺ and Ln³⁺ were determined by UVvis absorption spectroscopy. Ln-PQQ complexes in aqueous solution were analyzed by steady-state and time-resolved fluorescence spectroscopy. The thermodynamic and kinetic parameters describing the equilibrium were obtained by variable-temperature and proton exchange spectroscopy (EXSY) NMR, as well as DFT calculations. Results demonstrated a Ln-dependent exchange rate for PQQ hydration equilibrium, the late and more Lewis acidic Ln³⁺ having the stronger impact.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112924"},"PeriodicalIF":3.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906611","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}