title: Ability of N-acetylcarnosine to protect lens crystallins from oxidation and oxidative damage by radical probe mass spectrometry (RP-MS).
abstract: The application of Radical Probe Mass Spectrometry based on protein footprinting studies is described to investigate the effectiveness of the antioxidant N-acetylcarnosine (NAC) in preventing oxidative damage to lens crystallins present in the eye of mammals. Despite separate clinical trials which have reported the benefit of administering NAC to the eye as a 1% topical solution for the treatment of human cataract, no evidence was found to suggest that the antioxidant had any significant direct effect on reducing the levels of oxidation within the most abundant lens crystallins, α and β-crystallin, at the molecular level at increasing concentrations of NAC. The results of this laboratory study suggest that the therapeutic benefit demonstrated in clinical trials is associated with the nature or formulation of the topical solution and/or that the mode of action of NAC as an antioxidant is not a direct one.
authors.affiliation: School of Molecular Bioscience, University of Sydney, Sydney, Australia.
authors.forename: Ji-won
authors.initials: JW
authors.lastname: Ha
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Schwahn
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Downard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002336:Carnosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D002417:Cattle; D003459:Crystallins / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000187:drug effects*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D020543:Proteome / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014357:Trypsin / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003459:Crystallins; D010446:Peptide Fragments; D020543:Proteome; C033681:N-acetylcarnosine; D002336:Carnosine; D014357:Trypsin