Pourbaix Diagram, Proton-Coupled Electron Transfer, and Decay Kinetics of a Protein Tryptophan Radical: Comparing the Redox Properties of W₃₂^• and Y₃₂^• Generated Inside the Structurally Characterized α₃W and α₃Y Proteins.

ABSTRACT: Protein-based "hole" hopping typically involves spatially arranged redox-active tryptophan or tyrosine residues. Thermodynamic information is scarce for this type of process. The well-structured α₃W model protein was studied by protein film square wave voltammetry and transient absorption spectroscopy to obtain a comprehensive thermodynamic and kinetic description of a buried tryptophan residue. A Pourbaix diagram, correlating thermodynamic potentials (E°') with pH, is reported for W₃₂ in α₃W and compared to equivalent data recently presented for Y₃₂ in α₃Y ( Ravichandran , K. R. ; Zong , A. B. ; Taguchi , A. T. ; Nocera , D. G. ; Stubbe , J. ; Tommos , C. J. Am. Chem. Soc. 2017 , 139 , 2994 - 3004 ). The α₃W Pourbaix diagra

SUBMITTER: Glover SD 

PROVIDER: S-EPMC5762255 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature