title: Correlating C-H bond cleavage with molybdenum reduction in xanthine oxidase.
abstract: We have performed a computational study of substrate C-H bond activation in enzymes of the XO family. The C-H H-atom for all XO substrates studied is transferred to the terminal sulfido at the transition state with near neutral charge, and this is consistent with both Mo=S π→ C-H σ* and C-H σ→Mo=S π* donor-acceptor interactions activating the C-H bond. A C-H bond scission and Mo reduction appear to be highly correlated along the reaction coordinate for all XO substrates studied, with Mo reduction being a continuous and exponential function of C-H bond breaking along the reaction coordinate.
authors.affiliation: Department of Chemistry and Chemical Biology, The University of New Mexico, MSC02 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA. mkirk@unm.edu
authors.forename: Martin L
authors.initials: ML
authors.lastname: Kirk
authors.forename: Abebe
authors.initials: A
authors.lastname: Berhane
mesh_terms: D003198:Computer Simulation; D015394:Molecular Structure; D008982:Molybdenum / Q000737:chemistry*; D010084:Oxidation-Reduction; D014969:Xanthine Oxidase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008982:Molybdenum; D014969:Xanthine Oxidase