Journal of Biological Inorganic Chemistry最新文献

{"title":"Pre-clinical evaluation of 99mTc-labeled chalcone derivative for amyloid-β imaging post-head trauma","authors":"Garima Mann,&nbsp;Shivani Daksh,&nbsp;Nikhil Kumar,&nbsp;Ankur Kaul,&nbsp;B. G. Roy,&nbsp;M. Thirumal,&nbsp;Anupama Datta","doi":"10.1007/s00775-024-02049-x","DOIUrl":"10.1007/s00775-024-02049-x","url":null,"abstract":"<div><p>Aβ₄₂ plaque formation is one of the preliminary pathologic events that occur post traumatic brain injury (TBI) which is also among the most noteworthy hallmarks of AD. Their pre symptomatic detection is therefore vital for better disease management. Chalcone–picolinic acid chelator derivative, 6‐({[(6‐carboxypyridin‐2‐yl)methyl](2‐{4‐[(2E)‐3‐[4‐(dimethyl amino)phenyl]prop‐2‐enoyl]phenoxy}ethyl)amino}methyl)pyridine‐2‐carboxylic acid, Py-chal was synthesized to selectively identify amyloid plaques formed post head trauma using SPECT imaging by stable complexation to ^99mTc with &gt; 97% efficiency without compromising amyloid specificity. The binding potential of the Py-chal ligand to amyloid plaques remained high as confirmed by in vitro binding assay and photophysical spectra. Further, the Py-chal complex stained amyloid aggregates in the brain sections of rmTBI mice model. In vivo scintigraphy in TBI mice model displayed high uptake followed by high retention while the healthy rabbits displayed higher brain uptake followed by a rapid washout attributed to absence of amyloid plaques. Higher uptake in brain of TBI model was also confirmed by ex vivo biodistribution analysis wherein brain uptake of 3.38 ± 0.2% ID/g at 2 min p.i. was observed for TBI mice model. This was followed by prolonged retention and more than twofold higher activity as compared to sham mice brain. This preliminary data suggests the specificity of the radiotracer for amyloid detection post head trauma and applicability of ^99mTc labeled Py-chal complex for TBI-induced β-amyloid SPECT imaging.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 2","pages":"187 - 199"},"PeriodicalIF":2.7,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140582140","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}

{"title":"Triggering antibacterial activity of a common plant by biosorption of selected heavy metals","authors":"Mária Kováčová,&nbsp;Halyna Bodnár Yankovych,&nbsp;Adrian Augustyniak,&nbsp;Mariano Casas-Luna,&nbsp;Michaela Remešová,&nbsp;Lenka Findoráková,&nbsp;Martin Stahorský,&nbsp;Ladislav Čelko,&nbsp;Matej Baláž","doi":"10.1007/s00775-024-02045-1","DOIUrl":"10.1007/s00775-024-02045-1","url":null,"abstract":"<div><p>The presented study proposes an efficient utilization of a common <i>Thymus serpyllum</i> L. (wild thyme) plant as a highly potent biosorbent of Cu(II) and Pb(II) ions and the efficient interaction of the copper-laden plant with two opportunistic bacteria. Apart from biochars that are commonly used for adsorption, here we report the direct use of native plant, which is potentially interesting also for soil remediation. The highest adsorption capacity for Cu(II) and Pb(II) ions (<i>q</i>_e = 12.66 and 53.13 mg g⁻¹, respectively) was achieved after 10 and 30 min of adsorption, respectively. Moreover, the Cu-laden plant was shown to be an efficient antibacterial agent against the bacteria <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>, the results being slightly better in the former case. Such an activity is enabled only via the interaction of the adsorbed ions effectively distributed within the biological matrix of the plant with bacterial cells. Thus, the sustainable resource can be used both for the treatment of wastewater and, after an effective embedment of metal ions, for the fight against microbes.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 2","pages":"201 - 216"},"PeriodicalIF":2.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-024-02045-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140585589","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}

{"title":"Silver ciprofloxacin (CIPAG): a multitargeted metallodrug in the development of breast cancer therapy","authors":"Christina N. Banti,&nbsp;Foteini D. Kalousi,&nbsp;Anna-Maria G. Psarra,&nbsp;Eleni E. Moushi,&nbsp;Demetres D. Leonidas,&nbsp;Sotiris K. Hadjikakou","doi":"10.1007/s00775-024-02048-y","DOIUrl":"10.1007/s00775-024-02048-y","url":null,"abstract":"<div><p>The anti-proliferative activity of the known metalloantibiotic {[Ag(CIPH)₂]NO₃∙0.75MeOH∙1.2H₂O} (<b>CIPAG</b>) (CIPH = ciprofloxacin) against the human breast adenocarcinoma cancer cells MCF-7 (hormone dependent (HD)) and MDA-MB-231 (hormone independent (HI)) is evaluated. The in vitro toxicity and genotoxicity of the metalloantibiotic were estimated toward fetal lung fibroblast (MRC-5) cells. The molecular mechanism of the <b>CIPAG</b> activity against MCF-7 cells was clarified by the (i) cell morphology, (ii) cell cycle arrest, (iii) mitochondrial membrane permeabilization, and (iv) by the assessment of the possible differential effect of <b>CIPAG</b> on estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) transcriptional activation, applying luciferase reporter gene assay. Moreover, the ex vivo mechanism of <b>CIPAG</b> was clarified by its binding affinity toward calf thymus (CT-DNA).</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 2","pages":"177 - 186"},"PeriodicalIF":2.7,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-024-02048-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602067","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}

{"title":"Probing calmodulin–NO synthase interactions via site-specific infrared spectroscopy: an introductory investigation","authors":"Swapnil Singh,&nbsp;Yadav Prasad Gyawali,&nbsp;Ting Jiang,&nbsp;Gregory S. Bukowski,&nbsp;Huayu Zheng,&nbsp;Haikun Zhang,&nbsp;Rebecca Owopetu,&nbsp;Megan C. Thielges,&nbsp;Changjian Feng","doi":"10.1007/s00775-024-02046-0","DOIUrl":"10.1007/s00775-024-02046-0","url":null,"abstract":"<div><p>Calmodulin (CaM) binds to a linker between the oxygenase and reductase domains of nitric oxide synthase (NOS) to regulate the functional conformational dynamics. Specific residues on the interdomain interface guide the domain-domain docking to facilitate the electron transfer in NOS. Notably, the docking interface between CaM and the heme-containing oxygenase domain of NOS is isoform specific, which is only beginning to be investigated. Toward advancing understanding of the distinct CaM–NOS docking interactions by infrared spectroscopy, we introduced a cyano-group as frequency-resolved vibrational probe into CaM individually and when associated with full-length and a bi-domain oxygenase/FMN construct of the inducible NOS isoform (iNOS). Site-specific, selective labeling with <i>p</i>-cyano-<span>l</span>-phenylalanine (<i>CN</i>F) by amber suppression of CaM bound to the iNOS has been accomplished by protein coexpression due to the instability of recombinant iNOS protein alone. We introduced <i>CN</i>F at residue 108, which is at the putative CaM–heme (NOS) docking interface. <i>CN</i>F was also introduced at residue 29, which is distant from the docking interface. FT IR data show that the 108 site is sensitive to CaM–NOS complex formation, while insensitivity to its association with the iNOS protein or peptide was observed for the 29 site. Moreover, narrowing of the IR bands at residue 108 suggests the C≡N probe experiences a more limited distribution of environments, indicating side chain restriction apparent for the complex with iNOS. This initial work sets the stage for residue-specific characterizations of structural dynamics of the docked states of NOS proteins.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 2","pages":"243 - 250"},"PeriodicalIF":2.7,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140585588","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}

{"title":"Collaborations in the Spanish-Speaking Bioinorganic Community","authors":"Patrick Gamez,&nbsp;Luis Lemus","doi":"10.1007/s00775-024-02047-z","DOIUrl":"10.1007/s00775-024-02047-z","url":null,"abstract":"","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 1","pages":"1 - 1"},"PeriodicalIF":2.7,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140189308","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}

{"title":"Mononuclear η6-arene ruthenium(II) complexes with pyrazolyl–pyridazine ligands: synthesis, CT-DNA binding, reactivity towards glutathione, and cytotoxicity","authors":"Amos K. Kanyora,&nbsp;Reinner O. Omondi,&nbsp;Peter Ongoma,&nbsp;Josiah O. Omolo,&nbsp;Athi Welsh,&nbsp;Sharon Prince,&nbsp;Joel Gichumbi,&nbsp;Allen Mambanda,&nbsp;Gregory S. Smith","doi":"10.1007/s00775-024-02043-3","DOIUrl":"10.1007/s00775-024-02043-3","url":null,"abstract":"<div><p>Organometallic η⁶-arene ruthenium(II) complexes with 3-chloro-6-(1<i>H</i>-pyrazol-1-yl)pyridazine (<b>Ru1</b>, <b>Ru2,</b> and <b>Ru5</b>) and 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine (<b>Ru3</b>-<b>4)</b> N,N’ heterocyclic and η⁶-arene (cymene (<b>Ru1</b>-<b>4</b>) or toluene (<b>Ru 5</b>)) have been synthesized. The ruthenium(II) complexes have common “three-legged piano-stool” pseudo-octahedral structures known for half-sandwich complexes. Evolution of their UV–Visible absorption spectra in PBS buffer or DMSO over 24 h confirmed their good solvolysis stability. Titrations of the complexes with the calf thymus DNA (CT-DNA) were monitored using UV–Visible absorption and fluorescence spectroscopies. The complexes interact moderately with CT-DNA and their binding constants are in the order of 10⁴ M⁻¹. Competitive binding of the complexes to a DNA-Hoechst 33,258 depicted competitive displacement of Hoechst from DNA’s minor grooves. These complexes bind to glutathione forming GSH-adducts through S coordination by replacement of a halide, with the iodo-analogues having higher binding constants than the chloro-complexes. Cyclic voltammograms of the complexes exhibited one electron-transfer quasi-reversible process. Trends in the molecular docking data of <b>Ru1-5</b>/DNA were similar to those for DNA binding constants. Of the five, only <b>Ru1</b>, <b>Ru3</b> and <b>Ru5</b> showed some activity (moderate) against the MCF-7 breast cancer cells with IC₅₀ values in the range of 59.2–39.9 for which <b>Ru5</b> was the most active. However, the more difficult-to-treat cell line, MDA-MB 231 cell was recalcitrant to the treatment by these complexes.</p><h3>Graphical abstract</h3><p>Molecular docking simulations visualized the interactions of arene Ru(II) complexes with CT-DNA via minor grooving. The trends were corroborated by electrochemical and cytotoxicity data.</p>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 2","pages":"251 - 264"},"PeriodicalIF":2.7,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140142605","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}

{"title":"Altered conformational dynamics contribute to species-specific effects of cytochrome c mutations on caspase activation","authors":"Thomas C. Chin,&nbsp;Sigurd M. Wilbanks,&nbsp;Elizabeth C. Ledgerwood","doi":"10.1007/s00775-024-02044-2","DOIUrl":"10.1007/s00775-024-02044-2","url":null,"abstract":"<div><p>Variants in the gene encoding human cytochrome <i>c</i> (<i>CYCS</i>) cause mild autosomal dominant thrombocytopenia. Despite high sequence conservation between mouse and human cytochrome <i>c</i>, this phenotype is not recapitulated in mice for the sole mutant (G41S) that has been investigated. The effect of the G41S mutation on the in vitro activities of cytochrome <i>c</i> is also not conserved between human and mouse. Peroxidase activity is increased in both mouse and human G41S variants, whereas apoptosome activation is increased for human G41S cytochrome <i>c</i> but decreased for mouse G41S cytochrome <i>c</i>. These apoptotic activities of cytochrome <i>c</i> are regulated at least in part by conformational dynamics of the main chain. Here we use computational and in vitro approaches to understand why the impact of the G41S mutation differs between mouse and human cytochromes <i>c</i>. The G41S mutation increases the inherent entropy and main chain mobility of human but not mouse cytochrome <i>c</i>. Exclusively in human G41S cytochrome <i>c</i> this is accompanied by a decrease in occupancy of H-bonds between protein and heme during simulations. These data demonstrate that binding of cytochrome <i>c</i> to Apaf-1 to trigger apoptosome formation, but not the peroxidase activity of cytochrome <i>c</i>, is enhanced by increased mobility of the native protein conformation.</p></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 2","pages":"169 - 176"},"PeriodicalIF":2.7,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11098916/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140108729","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}

{"title":"Cytotoxicity of bismuth(III) dithiocarbamate derivatives by promoting a mitochondrial-dependent apoptotic pathway and suppressing MCF-7 breast adenocarcinoma cell invasion","authors":"Pit Foong Chan,&nbsp;Kok Pian Ang,&nbsp;Roslida Abd Hamid","doi":"10.1007/s00775-023-02041-x","DOIUrl":"10.1007/s00775-023-02041-x","url":null,"abstract":"<div><p>We previously reported that the bismuth(III) dithiocarbamate derivative, bismuth diethyldithiocarbamate (<b>1</b>) exhibited greater cytotoxicity while inducing apoptosis via the intrinsic pathway in MCF-7 cells. We further evaluated the other bismuth(III) dithiocarbamate derivatives, Bi[S₂CNR]₃, with R = (CH₂CH₂OH)(ⁱPr), (CH₂)₄, and (CH₂CH₂OH)(CH₃), denoted as <b>2</b>, <b>3</b>, and <b>4</b>, respectively, in the same MCF-7 cell line. <b>2</b>–<b>4</b> were found to exhibit IC₅₀ values of 10.33 ± 0.06 µM, 1.07 ± 0.01 µM and 25.37 ± 0.12 µM, respectively, compared to that of cisplatin at 30.53 ± 0.23 µM. Apoptotic promotion via the mitochondrial-dependent pathway was due to the elevation of intracellular reactive oxygen species (ROS), promotion of caspases, release of cytochrome <i>c</i>, fragmentation of DNA, and results of staining assay observed in all compound-treated cells. <b>2</b>–<b>4</b> are also capable of suppressing MCF-7 cell invasion and modulate Lys-48 also Lys-63 linked polyubiquitination, leading to proteasomal degradation. Analysis of gene expression via qRT-PCR revealed their modulation, which supported all activities conducted upon treatment with <b>2</b>–<b>4</b>. Altogether, bismuth dithiocarbamate derivatives, with bismuth(III) as the metal center bound to ligands, isopropyl ethanol, pyrrolidine, and methyl ethanol dithiocarbamate, are potential anti-breast cancer agents that induce apoptosis and suppress metastasis. Further studies using other breast cancer cell lines and in vivo studies are recommended to clarify the anticancer effects of these compounds.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 2","pages":"217 - 241"},"PeriodicalIF":2.7,"publicationDate":"2024-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139899221","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}

{"title":"Effect of Pb-exposure and B vitamin deficiencies on δ-aminolevulinic acid dehydratase activity among workers from Pb recycling plants","authors":"Vinay Kumar Adepu,&nbsp;H. S. Santosh Kumar,&nbsp;Kalahasthi Ravibabu,&nbsp;Raju Nagaraju","doi":"10.1007/s00775-023-02042-w","DOIUrl":"10.1007/s00775-023-02042-w","url":null,"abstract":"<div><p>Previous studies reported that Pb exposure causes a negative association with delta-aminolevulinic acid dehydratase activity (δ-ALAD), but the impact of Pb exposure (dose and time), B vitamin deficiencies, and lifestyle factors needs to be explored. In this study, the impact of Pb exposure, B vitamin deficiencies, and lifestyle factors on δ-ALAD activity among workers exposed to Pb from the Pb-recycling process was evaluated. Blood lead levels (BLLs), B vitamins (B6, B9, and B12), hematological factors (Hb% and HCT), lifestyle factors, and δ-ALAD activity was assessed in 170 male Pb-exposed workers engaged in the Pb recycling process. BLLs are estimated using the ICP-OES method. B vitamins in serum samples from workers were determined using the ELISA method. The δ-ALAD activity in whole blood samples was determined using the spectrophotometer method. The lifestyle factors were collected using a standard questionnaire. The δ-ALAD activity was significantly decreased in workers with the habits of alcohol use, tobacco consumption, hematocrit &lt; 41%, mild and moderate categories of anemia, vitamin B6 and B12 deficiency, and BLL categories of 10–30, 30–50, and &gt; 50 µg/dL. Multiple regression analysis revealed that the independent variables of alcohol consumption (β = − 0.170; P = 0.025), BLLs (β = − 0.589; P = 0.001) and Hb% (β = 0.183; P = 0.001) significantly influenced the δ-ALAD activity with 44.2% (R² = 0.442). Among the workers exposed to Pb from the Pb recycling plant, δ-ALAD activity was considerably reduced by Pb exposure, B vitamin deficiency, hematological parameters, and lifestyle factors.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 3","pages":"375 - 383"},"PeriodicalIF":2.7,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139574637","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}

{"title":"Spectroscopic and computational investigations of Cobalt(II) binding to the innate immune protein human calprotectin","authors":"Michelle M. Killian,&nbsp;Megan B. Brophy,&nbsp;Elizabeth M. Nolan,&nbsp;Thomas C. Brunold","doi":"10.1007/s00775-023-02034-w","DOIUrl":"10.1007/s00775-023-02034-w","url":null,"abstract":"<div><p>Human calprotectin (CP) is an innate immune protein that participates in the metal-withholding response to infection by sequestering essential metal nutrients from invading microbial pathogens. CP is comprised of S100A8 (<i>α</i> subunit, 10.8 kDa) and S100A9 (<i>β</i> subunit, 13.2 kDa). Two transition-metal binding sites of CP form at the S100A8/S100A9 dimer interface. Site 1 is a His₃Asp motif comprised of His83 and His87 from the S100A8 subunit and His20 and Asp30 from the S100A9 subunit. Site 2 is an unusual hexahistidine motif composed of S100A8 residues His17 and His27 and S100A9 residues His91, His95, His103, and His105. In the present study, the His₃Asp and His₆ sites of CP were further characterized by utilizing Co²⁺ as a spectroscopic probe. Magnetic circular dichroism spectroscopy was employed in conjunction with electron paramagnetic resonance spectroscopy and density functional theory computations to characterize the Co²⁺-bound S100A8(C42S)/S100A9(C3S) CP-Ser variant and six site variants that allowed the His₃Asp and His₆ sites to be further probed. Our results provide new insight into the metal-binding sites of CP-Ser and the effect of amino acid substitutions on the structure of site 2.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":"29 1","pages":"127 - 137"},"PeriodicalIF":2.7,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139484704","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}