title: Synthesis of Site-Specifically13C Labeled Linoleic Acids.
abstract: Soybean lipoxygenase-1 (SLO-1) catalyzes the C-H abstraction from the reactive carbon (C-11) in linoleic acid as the first and rate-determining step in the formation of alkylhydroperoxides. While previous labeling strategies have focused on deuterium labeling to ascertain the primary and secondary kinetic isotope effects for this reaction, there is an emerging interest and need for selectively enriched13C isotopologues. In this report, we present synthetic strategies for site-specific13C labeled linoleic acid substrates. We take advantage of a Corey-Fuchs formyl to terminal13C-labeled alkyne conversion, using13CBr4as the labeling source, to reduce the number of steps from a previous fatty acid13C synthetic labeling approach. The labeled linoleic acid substrates are useful as nuclear tunneling markers and for extracting active site geometries of the enzyme-substrate complex in lipoxygenase.
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720; Quantitative Institutes of Biosciences, University of California, Berkeley, Berkeley, California, 94720.
authors.forename: Adam R
authors.initials: AR
authors.lastname: Offenbacher
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720; Quantitative Institutes of Biosciences, University of California, Berkeley, Berkeley, California, 94720.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720; Quantitative Institutes of Biosciences, University of California, Berkeley, Berkeley, California, 94720; Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, California, 94720.
authors.forename: Judith P
authors.initials: JP
authors.lastname: Klinman
keywords: Secondary isotope effects; hydrogen tunneling; linoleic acid; lipoxygenase