Bragança PMS, Carepo MSP, Pauleta SR, Pinter TBJ, Elia M, Cordas CM, Moura I, Pecoraro VL, Moura JJG. Incorporation of a molybdenum atom in a Rubredoxin-type Centre of a de novo-designed α
3DIV-L21C three-helical bundle peptide.
J Inorg Biochem 2023;
240:112096. [PMID:
36603242 PMCID:
PMC11232944 DOI:
10.1016/j.jinorgbio.2022.112096]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/17/2022] [Accepted: 12/04/2022] [Indexed: 12/24/2022]
Abstract
The rational design and functionalization of small, simple, and stable peptides scaffolds is an attractive avenue to mimic catalytic metal-centres of complex proteins, relevant for the design of metalloenzymes with environmental, biotechnological and health impacts. The de novo designed α3DIV-L21C framework has a rubredoxin-like metal binding site and was used in this work to incorporate a Mo-atom. Thermostability studies using differential scanning calorimetry showed an increase of 4 °C in the melting temperature of the Mo-α3DIV-L21C when compared to the apo-α3DIV-L21C. Circular dichroism in the visible and far-UV regions corroborated these results showing that Mo incorporation provides stability to the peptide even though there were almost no differences observed in the secondary structure. A formal reduction potential of ∼ -408 mV vs. NHE, pH 7.6 was determined. Combining electrochemical results, EPR and UV-visible data we discuss the oxidation state of the molybdenum centre in Mo-α3DIV-L21C and propose that is mainly in a Mo (VI) oxidation state.
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