Journal of Inorganic Biochemistry最新文献

{"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}

{"title":"A 4-phenylbutyric acid-conjugated platinum diimine complex: Photocytotoxicity, cell cycle arrest and apoptosis in vitro","authors":"Xuemei Guo,&nbsp;Yuxin Lu,&nbsp;Xu Zhang,&nbsp;Xin Wang,&nbsp;Hongfei Wang,&nbsp;Zhigang Zhang","doi":"10.1016/j.jinorgbio.2025.112930","DOIUrl":"10.1016/j.jinorgbio.2025.112930","url":null,"abstract":"<div><div>4-phenylbutyric acid (PBA) is a class <strong>I</strong> and <strong>II</strong> histone deacetylase inhibitor, which can decrease cell proliferation, enhance cell differentiation, and induce apoptosis and cell cycle arrest in various cancer cells. PBA-modified photoactive platinum diimine complex has been prepared and characterized to augment its photodynamic therapy efficacy. Its ability to generate singlet oxygen, behavior in the presence of esterase, photocytotoxicity, cell cycle distribution, and apoptosis-inducing ability in MCF-7 cells have also been studied. The results suggested that the PBA-modified platinum diimine complex could act as a good singlet oxygen producer, release PBA in the presence of esterase, induce potent photocytotoxicity in tumor cells with a IC₅₀ value of 3.67 ± 0.67 μM, arrest cell cycle at S phase, and induce cell death <em>via</em> apoptosis with the percentage of total apoptotic cells being 34.65 %. The results also revealed that PBA might be able to modulate the mode of cell cycle arrest induced by the photosensitizer in tumor cells.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112930"},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852036","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":"Mössbauer studies of the redox state of the ferric uptake regulator [2Fe–2S]2+ cluster in Escherichia coli","authors":"Chelsey R. Fontenot ,&nbsp;Thomas Hoepner ,&nbsp;Jin Xiong ,&nbsp;Huangen Ding ,&nbsp;Codrina V. Popescu","doi":"10.1016/j.jinorgbio.2025.112928","DOIUrl":"10.1016/j.jinorgbio.2025.112928","url":null,"abstract":"<div><div>The Ferric uptake regulator (Fur) proteins from <em>Haemophilus influenzae</em> and <em>Escherichia coli</em> overexpressed in <em>E. coli</em> cells (MC4100) grown in M9 medium supplemented with ⁵⁷Fe were studied with Mössbauer spectroscopy. Previous studies have shown that Fur proteins from <em>H. influenzae</em> and <em>E. coli</em> bind a [2Fe–2S]²⁺ cluster in response to elevation of intracellular free iron content. Here we find that when the [2Fe–2S]²⁺ clusters in purified Fur proteins are reduced with dithionite, the reduced clusters are quickly decomposed, forming compounds with two distinct spectral signatures of high spin Fe(II) in tetrahedral and octahedral coordination, respectively. The instability of the reduced [2Fe-2S]¹⁺ cluster in Fur is unique, as the [2Fe–2S]²⁺ clusters in many other proteins can reversibly undergo one-electron reduction-oxidation. The Mössbauer spectra of whole <em>E. coli</em> cells overexpressing Fur proteins show a quadrupole doublet with the isomer shift of δ₁ = 0.28 mm/s and ΔE_Q1 = 0.52 mm/s, typical for oxidized [2Fe-2S]²⁺ clusters and identical with that in the purified Fur protein. The corresponding spectra in large applied magnetic fields show the diamagnetic pattern that unambiguously reveals an exchange-coupled system with a diamagnetic electronic ground state, which confirms its assignment to the oxidized [2Fe-2S]²⁺ cluster clusters from Fur. No reduced [2Fe-2S]¹⁺ clusters of Fur are observed in the whole-cell <em>E. coli</em> spectra. The Mössbauer spectra of the whole-cell <em>E. coli</em> without the Fur expression do not contain the components associated with the [2Fe–2S]²⁺ cluster of Fur.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112928"},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877145","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":"Elucidating the metalation pathway of the Ec-1 metallothionein βE-domain: Insights into ZnII binding and protein folding","authors":"Rukmal Karunaratne ,&nbsp;Erik P. Willems ,&nbsp;Oliver Zerbe ,&nbsp;Eva Freisinger","doi":"10.1016/j.jinorgbio.2025.112931","DOIUrl":"10.1016/j.jinorgbio.2025.112931","url":null,"abstract":"<div><div>Metallothioneins (MTs) are small cysteine-rich proteins that preferentially bind d¹⁰ metal ions such as Zn^II, Cu^I, and Cd^II, playing essential roles in metal ion homeostasis and detoxification. The E_c-1 metallothionein from <em>Triticum aestivum</em> (common bread wheat) was the first plant metallothionein for which a 3D structure was successfully determined, although this structure represents only the fully metalated state of the protein. In this study, we aim to elucidate the metalation pathway of the β_E-domain of wheat E_c-1. This domain features a mononuclear Zn^II binding site composed of two cysteine and two highly conserved histidine residues, reminiscent of the Zn-finger motifs found in certain proteins. Moreover, the domain forms a trinuclear Zn₃Cys₉ cluster, similar to the β-cluster motif observed, for example, in vertebrate MTs. To investigate the metalation pathway of the β_E-domain, we combined nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and targeted cysteine modification techniques. Our results confidently identify the sequential binding site regions for each of the four Zn^II ions and reveal intriguing, unexpected insights into the folding pathway of the peptide backbone.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112931"},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868923","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":"The interplay between the myeloperoxidase-hypochlorous acid system, heme oxygenase, and free iron in inflammatory diseases","authors":"Mia M. Biernat ,&nbsp;Olivia G. Camp ,&nbsp;Daniel N. Moussa ,&nbsp;Awoniyi O. Awonuga ,&nbsp;Husam M. Abu-Soud","doi":"10.1016/j.jinorgbio.2025.112927","DOIUrl":"10.1016/j.jinorgbio.2025.112927","url":null,"abstract":"<div><div>Accumulated unbound free iron (Fe(II or III)) is a redox engine generating reactive oxygen species (ROS) that promote oxidative stress and inflammation. Iron is implicated in diseases with free radical pathology including cardiovascular, neurodegenerative, reproductive disorders, and some types of cancer. While many studies focus on iron overload disorders, few explore the potential link between the myeloperoxidase-hypochlorous acid (MPO-HOCl) system and localized iron accumulation through heme and iron‑sulfur (Fe<img>S) cluster protein destruction. Although inducible heme oxygenase (HO-1), the rate-limiting enzyme in heme catabolism, is frequently associated with these diseases, we hypothesize that HOCl also contributes to the generation of free iron and heme degradation products. Furthermore, HO-1 and HOCl may play a dual role in free iron accumulation by regulating the activity of key iron metabolism proteins. Enzymatic and non-enzymatic modulators, as well as scavengers of HOCl, can help prevent heme destruction and reduce the accumulation of free iron. Given iron's role in disease progression and severity, identifying the primary sources, mechanisms, and mediators involved in free iron generation is crucial for developing effective pharmacological treatments. Further investigation focusing on the specific contributions of the MPO-HOCl system and free iron is necessary to explore novel strategies to mitigate its harmful effects in biological systems.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112927"},"PeriodicalIF":3.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858946","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":"Interaction of half-sandwich Rh(III) ion and some of its complexes with endogenous imidazole derivatives","authors":"Azza A. Hassoon ,&nbsp;Attila Szorcsik ,&nbsp;Tamás Gajda","doi":"10.1016/j.jinorgbio.2025.112913","DOIUrl":"10.1016/j.jinorgbio.2025.112913","url":null,"abstract":"<div><div>An increasing number of {Rh(η⁵-Cp*)}²⁺ complexes are reported to possess promising medical, mostly anticancer activities. In parallel, growing interest has also focused on the interactions between {Rh(η⁵-Cp*)}²⁺-based metallodrugs and macromolecular components of biological fluids, since the biospeciation of these potential metallodrugs may strongly influence their overall pharmacological properties. Less attention was paid to the interaction of {Rh(η⁵-Cp*)}²⁺ complexes with low molecular mass (LMM) constituents of biological fluids, which may also have significant impact on their biospeciation. From this point of view, the biogenic imidazole derivatives are the most important, since the primary binding sites of proteins for {Rh(η⁵-Cp*)}²⁺ cation are the surface histidine groups. Several imidazole containing endogenous LMM components are known, which have relevant concentrations in certain biological fluids, such as plasma. Therefore, here we report systematic solution thermodynamic and solution structural (potentiometric, UV–Vis, ESI-MS and ¹H NMR) study on the interaction of {Rh(η⁵-Cp*)}²⁺ cation with thyrotropin-releasing hormone (TRH, pGlu-His-Pro-NH₂, <strong>L</strong>^{<strong>1</strong>}), carnosine (β-alanyl-histidine, <strong>L</strong>^{<strong>2</strong>}), carcinine (β-alanyl-histamine, <strong>L</strong>^{<strong>3</strong>}), histidine (<strong>L</strong>^{<strong>4</strong>}) and the human growth modulator tripeptide GHK (Gly-His-Lys, <strong>L</strong>^{<strong>5</strong>}). The results indicate, that these biogenic ligands, especially histidine and GHK, possess very high binding ability towards {Rh(η⁵-Cp*)}²⁺ cation, higher than for the well-known histidine-peptide binder copper(II). In addition, we also studied the interaction of two simple [Rh(η⁵-Cp*)(A)Cl]⁺ complexes (where A = 2,2′-bipyridyl (<strong>bpy</strong>) or ethylenediamine (<strong>en</strong>)), as mimics of potentially anticancer compounds, with the above listed endogenous imidazole derivatives. Beside the formation of ternary [Rh(η⁵-Cp*)(A)(L)] complexes, histidine and GHK, having exceptionally high {Rh(η⁵-Cp*)}²⁺ binding ability, are also able to displace <strong>en</strong> or <strong>bpy</strong> from the coordination sphere of Rh(III). Moreover, histidine and GHK successfully compete even with human serum albumin under near physiological conditions, and thus may have fundamental effect on the blood transport and biodistribution of any {Rh(η⁵-Cp*)}²⁺-based bioactive compounds.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"270 ","pages":"Article 112913"},"PeriodicalIF":3.8,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829667","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}