title: Protein reactivity with singlet oxygen: Influence of the solvent exposure of the reactive amino acid residues.
abstract: The singlet oxygen quenching rate constants were measured for three model proteins, bovine serum albumin, β-lactoglobulin and lysozyme. The results were analyzed by comparing them with the corresponding singlet oxygen quenching rate constants for a series of tripeptides with the basic formula GlyAAGly where the central amino acid (AA) was the oxidizable amino acid, tryptophan, tyrosine, methionine and histidine. It was found that the reaction rate constant in proteins can be satisfactorily modelled by the sum of the individual contributions of the oxidizable AA residues corrected for the solvent accessible surface area (SASA) effects. The best results were obtained when the SASA of the AA residues were determined by averaging over molecular dynamics simulated trajectories of the proteins. The limits of this geometrical correction of the AA residue reactivity are also discussed.
authors.affiliation: Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 Route de Gray, 25030 Besançon Cedex, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Sjöberg
authors.affiliation: Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 Route de Gray, 25030 Besançon Cedex, France. Electronic address: sarah.foley@univ-fcomte.fr.
authors.forename: Sarah
authors.initials: S
authors.lastname: Foley
authors.affiliation: National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Str., Magurele, Ilfov 077125, Romania.
authors.forename: Angela
authors.initials: A
authors.lastname: Staicu
authors.affiliation: National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Str., Magurele, Ilfov 077125, Romania.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Pascu
authors.affiliation: National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Str., Magurele, Ilfov 077125, Romania.
authors.forename: Mihail
authors.initials: M
authors.lastname: Pascu
authors.affiliation: Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 Route de Gray, 25030 Besançon Cedex, France.
authors.forename: Mironel
authors.initials: M
authors.lastname: Enescu
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D007700:Kinetics; D011506:Proteins / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D011506:Proteins; D012997:Solvents; D026082:Singlet Oxygen
keywords: Model proteins; Singlet oxygen quenching; Solvent accessible surface area; Tripeptides