title: Proton-coupled electron hopping in Ru-modified P. aeruginosa azurin.
abstract: We constructed two artificial multiple-step electron transfer (hopping) systems based on Pseudomonas aeruginosa azurin where a tyrosine (YOH) is situated between Ru(2,2'-bipyridine)2(imidazole)(histidine) and the native copper site: RuH107YOH109 and RuH124-YOH122. We investigated the rates of Cu(I) oxidation by flash-quench generated Ru(III) over a range of conditions that probed the role of proton-coupled oxidation/reduction of YOH in the reaction. Rates of Cu(I) oxidation were enhanced over single-step electron transfer by factors between 3 and 80, depending on specific scaffold and buffer conditions.
authors.affiliation: Beckman Institute, California Institute of Technology, Pasadena, CA, 91125, USA. j.warren@sfu.ca.|Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada. j.warren@sfu.ca.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Warren
authors.affiliation: Beckman Institute, California Institute of Technology, Pasadena, CA, 91125, USA.
authors.forename: Oliver S
authors.initials: OS
authors.lastname: Shafaat
authors.affiliation: Beckman Institute, California Institute of Technology, Pasadena, CA, 91125, USA.
authors.forename: Jay R
authors.initials: JR
authors.lastname: Winkler
authors.affiliation: Beckman Institute, California Institute of Technology, Pasadena, CA, 91125, USA. hbgray@caltech.edu.
authors.forename: Harry B
authors.initials: HB
authors.lastname: Gray
mesh_terms: D001400:Azurin / Q000737:chemistry*; D004583:Electrons; D011522:Protons; D011550:Pseudomonas aeruginosa / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D011522:Protons; D001400:Azurin; D012428:Ruthenium
keywords: Copper oxidation; RuIII oxidants