Reversible phenol oxidation and reduction in the structurally well-defined 2-Mercaptophenol-alpha(3)C protein.Tommos, C., Valentine, K.G., Martinez-Rivera, M.C., Liang, L., Moorman, V.R.
(2013) Biochemistry 52: 1409-1418
- PubMed: 23373469
- DOI: 10.1021/bi301613p
- Also Cited By: 2MI7
- PubMed Abstract:
- De novo proteins as models of radical enzymes
Tommos, C.,Skalicky, J.J.,Pilloud, D.L.,Wand, A.,Dutton, P.
(1999) Biochemistry 38: 9495
- Reversible voltammograms and a Pourbaix diagram for a protein tyrosine radical.
Berry, B.W.,Martinez-Rivera, M.C.,Tommos, C.
(2012) Proc.Natl.Acad.Sci.USA 109: 9739
- De novo proteins as models of radical enzymes.
Tommos, C.,Skalicky, J.J.,Pilloud, D.L.,Wand, A.J.,Dutton, P.L.
(1999) Biochemistry 38: 9495
- Electrochemical and structural properties of a protein system designed to generate tyrosine Pourbaix diagrams.
Martinez-Rivera, M.C.,Berry, B.W.,Valentine, K.G.,Westerlund, K.,Hay, S.,Tommos, C.
(2011) J.Am.Chem.Soc. 133: 17786
- Structure of a de novo designed protein model of radical enzymes.
Dai, Q.H.,Tommos, C.,Fuentes, E.J.,Blomberg, M.R.,Dutton, P.L.,Wand, A.J.
(2002) J.Am.Chem.Soc. 124: 10952
- Moving a phenol hydroxyl group from the surface to the interior of a protein: effects on the phenol potential and pK(A).
Hay, S.,Westerlund, K.,Tommos, C.
(2005) Biochemistry 44: 11891
2-Mercaptophenol-α₃C serves as a biomimetic model for enzymes that use tyrosine residues in redox catalysis and multistep electron transfer. This model protein was tailored for electrochemical studies of phenol oxidation and reduction with specific e ...
2-Mercaptophenol-α₃C serves as a biomimetic model for enzymes that use tyrosine residues in redox catalysis and multistep electron transfer. This model protein was tailored for electrochemical studies of phenol oxidation and reduction with specific emphasis on the redox-driven protonic reactions occurring at the phenol oxygen. This protein contains a covalently modified 2-mercaptophenol-cysteine residue. The radical site and the phenol compound were specifically chosen to bury the phenol OH group inside the protein. A solution nuclear magnetic resonance structural analysis (i) demonstrates that the synthetic 2-mercaptophenol-α₃C model protein behaves structurally as a natural protein, (ii) confirms the design of the radical site, (iii) reveals that the ligated phenol forms an interhelical hydrogen bond to glutamate 13 (phenol oxygen-carboxyl oxygen distance of 3.2 ± 0.5 Å), and (iv) suggests a proton-transfer pathway from the buried phenol OH (average solvent accessible surface area of 3 ± 5%) via glutamate 13 (average solvent accessible surface area of the carboxyl oxygens of 37 ± 18%) to the bulk solvent. A square-wave voltammetry analysis of 2-mercaptophenol-α₃C further demonstrates that (v) the phenol oxidation-reduction cycle is reversible, (vi) formal phenol reduction potentials can be obtained, and (vii) the phenol-O(•) state is long-lived with an estimated lifetime of ≥180 millisecond. These properties make 2-mercaptophenol-α₃C a unique system for characterizing phenol-based proton-coupled electron transfer in a low-dielectric and structured protein environment.
Graduate Group in Biochemistry and Molecular Biophysics and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, United States. firstname.lastname@example.org