The pH-Induced Selectivity Between Cysteine or Histidine Coordinated Heme in an Artificial α-Helical Metalloprotein.

Autor: Koebke KJ; Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA., Kühl T; Laboratoire de Bioénergétique et Ingénierie des Protéines (UMR 7281), IMM FR3479, CNRS, Aix-Marseille Univ., Marseille, France., Lojou E; Laboratoire de Bioénergétique et Ingénierie des Protéines (UMR 7281), IMM FR3479, CNRS, Aix-Marseille Univ., Marseille, France., Demeler B; Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada., Schoepp-Cothenet B; Laboratoire de Bioénergétique et Ingénierie des Protéines (UMR 7281), IMM FR3479, CNRS, Aix-Marseille Univ., Marseille, France., Iranzo O; Institut des Sciences Moléculaires de Marseille (iSm2), Centrale Marseille, Aix-Marseille Univ., CNRS, Marseille, France., Pecoraro VL; Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA., Ivancich A; Laboratoire de Bioénergétique et Ingénierie des Protéines (UMR 7281), IMM FR3479, CNRS, Aix-Marseille Univ., Marseille, France.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2021 Feb 19; Vol. 60 (8), pp. 3974-3978. Date of Electronic Publication: 2020 Dec 23.
DOI: 10.1002/anie.202012673
Abstrakt: De Novo metalloprotein design assesses the relationship between metal active site architecture and catalytic reactivity. Herein, we use an α-helical scaffold to control the iron coordination geometry when a heme cofactor is allowed to bind to either histidine or cysteine ligands, within a single artificial protein. Consequently, we uncovered a reversible pH-induced switch of the heme axial ligation within this simplified scaffold. Characterization of the specific heme coordination modes was done by using UV/Vis and Electron Paramagnetic Resonance spectroscopies. The penta- or hexa-coordinate thiolate heme (9≤pH≤11) and the penta-coordinate imidazole heme (6≤pH≤8.5) reproduces well the heme ligation in chloroperoxidases or cyt P450 monooxygenases and peroxidases, respectively. The stability of heme coordination upon ferric/ferrous redox cycling is a crucial property of the construct. At basic pHs, the thiolate mini-heme protein can catalyze O 2 reduction when adsorbed onto a pyrolytic graphite electrode.
(© 2020 Wiley-VCH GmbH.)
Databáze: MEDLINE
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