title: Neighboring pyrrolidine amide participation in thioether oxidation. Methionine as a "hopping" site.
abstract: Methionine residues have been shown to function as efficient "hopping" sites in long-range electron transfer in model polyprolyl peptides. We suggest that a key to this ability of methionine is stabilization of the transient sulfur radical cation by neighboring proline amide participation. That is, in a model system a neighboring pyrrolidine amide lowers the oxidation potential of the thioether by over 0.5 V by formation of a two-center three-electron SO bond.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, United States. rglass@u.arizona.edu
authors.forename: Richard S
authors.initials: RS
authors.lastname: Glass
authors.forename: Christian
authors.initials: C
authors.lastname: Schöneich
authors.forename: George S
authors.initials: GS
authors.lastname: Wilson
authors.forename: Thomas
authors.initials: T
authors.lastname: Nauser
authors.forename: Takuhei
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Edward
authors.initials: E
authors.lastname: Lorance
authors.forename: Gary S
authors.initials: GS
authors.lastname: Nichol
authors.forename: Malika
authors.initials: M
authors.lastname: Ammam
mesh_terms: D000577:Amides / Q000737:chemistry*; D008715:Methionine / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011759:Pyrrolidines / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry
chemical_list: D000577:Amides; D011759:Pyrrolidines; D013455:Sulfur; D008715:Methionine; C032519:pyrrolidine