Levi A. Ekanger, Ruhi K. Shah, Matthew E. Porowski, Zach Ziolkowski, Alana Calello
{"title":"Spectroscopic, electrochemical, and kinetic trends in Fe(III)–thiolate disproportionation near physiologic pH","authors":"Levi A. Ekanger, Ruhi K. Shah, Matthew E. Porowski, Zach Ziolkowski, Alana Calello","doi":"10.1007/s00775-024-02051-3","DOIUrl":null,"url":null,"abstract":"<div><p>In addition to its primary oxygen-atom-transfer function, cysteamine dioxygenase (ADO) exhibits a relatively understudied anaerobic disproportionation reaction (ADO-Fe(III)-SR → ADO-Fe(II) + ½ RSSR) with its native substrates. Inspired by ADO disproportionation reactivity, we employ [Fe(tacn)Cl<sub>3</sub>] (tacn = 1,4,7-triazacyclononane) as a precursor for generating Fe(III)–thiolate model complexes in buffered aqueous media. A series of Fe(III)–thiolate model complexes are generated in situ using aqueous [Fe(tacn)Cl<sub>3</sub>] and thiol-containing ligands cysteamine, penicillamine, mercaptopropionate, cysteine, cysteine methyl ester, <i>N</i>-acetylcysteine, and <i>N</i>-acetylcysteine methyl ester. We observe trends in UV–Vis and electron paramagnetic resonance (EPR) spectra, disproportionation rate constants, and cathodic peak potentials as a function of thiol ligand. These trends will be useful in rationalizing substrate-dependent Fe(III)–thiolate disproportionation reactions in metalloenzymes.</p><h3>Graphical abstract</h3>\n<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":"291 - 301"},"PeriodicalIF":2.7000,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11111527/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"JBIC Journal of Biological Inorganic Chemistry","FirstCategoryId":"1","ListUrlMain":"https://link.springer.com/article/10.1007/s00775-024-02051-3","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
In addition to its primary oxygen-atom-transfer function, cysteamine dioxygenase (ADO) exhibits a relatively understudied anaerobic disproportionation reaction (ADO-Fe(III)-SR → ADO-Fe(II) + ½ RSSR) with its native substrates. Inspired by ADO disproportionation reactivity, we employ [Fe(tacn)Cl3] (tacn = 1,4,7-triazacyclononane) as a precursor for generating Fe(III)–thiolate model complexes in buffered aqueous media. A series of Fe(III)–thiolate model complexes are generated in situ using aqueous [Fe(tacn)Cl3] and thiol-containing ligands cysteamine, penicillamine, mercaptopropionate, cysteine, cysteine methyl ester, N-acetylcysteine, and N-acetylcysteine methyl ester. We observe trends in UV–Vis and electron paramagnetic resonance (EPR) spectra, disproportionation rate constants, and cathodic peak potentials as a function of thiol ligand. These trends will be useful in rationalizing substrate-dependent Fe(III)–thiolate disproportionation reactions in metalloenzymes.
期刊介绍:
Biological inorganic chemistry is a growing field of science that embraces the principles of biology and inorganic chemistry and impacts other fields ranging from medicine to the environment. JBIC (Journal of Biological Inorganic Chemistry) seeks to promote this field internationally. The Journal is primarily concerned with advances in understanding the role of metal ions within a biological matrix—be it a protein, DNA/RNA, or a cell, as well as appropriate model studies. Manuscripts describing high-quality original research on the above topics in English are invited for submission to this Journal. The Journal publishes original articles, minireviews, and commentaries on debated issues.