title: Unusual kinetic isotope effects of deuterium reinforced polyunsaturated fatty acids in tocopherol-mediated free radical chain oxidations.
abstract: Substitution of -CD2- at the reactive centers of linoleic and linolenic acids reduces the rate of abstraction of D by a tocopheryl radical by as much as 36-fold, compared to the abstraction of H from a corresponding -CH2- center. This H atom transfer reaction is the rate-determining step in the tocopherol-mediated peroxidation of lipids in human low-density lipoproteins, a process that has been linked to coronary artery disease. The unanticipated large kinetic isotope effects reported here for the tocopherol-mediated oxidation of linoleic and linolenic acids and esters suggests that tunneling makes this process favorable.
authors.affiliation: Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Connor R
authors.initials: CR
authors.lastname: Lamberson
authors.forename: Libin
authors.initials: L
authors.lastname: Xu
authors.forename: Hubert
authors.initials: H
authors.lastname: Muchalski
authors.forename: J Rafael
authors.initials: JR
authors.lastname: Montenegro-Burke
authors.forename: Vadim V
authors.initials: VV
authors.lastname: Shmanai
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Bekish
authors.forename: John A
authors.initials: JA
authors.lastname: McLean
authors.forename: Catherine F
authors.initials: CF
authors.lastname: Clarke
authors.forename: Mikhail S
authors.initials: MS
authors.lastname: Shchepinov
authors.forename: Ned A
authors.initials: NA
authors.lastname: Porter
mesh_terms: D003903:Deuterium / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D008077:Lipoproteins, LDL / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D024505:Tocopherols / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D008077:Lipoproteins, LDL; D003903:Deuterium; D024505:Tocopherols