title: (+)-Larreatricin hydroxylase, an enantio-specific polyphenol oxidase from the creosote bush (Larrea tridentata).
abstract: An enantio-specific polyphenol oxidase (PPO) was purified approximately 1,700-fold to apparent homogeneity from the creosote bush (Larrea tridentata), and its encoding gene was cloned. The posttranslationally processed PPO ( approximately 43 kDa) has a central role in the biosynthesis of the creosote bush 8-8' linked lignans, whose representatives, such as nordihydroguaiaretic acid and its congeners, have potent antiviral, anticancer, and antioxidant properties. The PPO primarily engenders the enantio-specific conversion of (+)-larreatricin into (+)-3'-hydroxylarreatricin, with the regiochemistry of catalysis being unambiguously established by different NMR spectroscopic analyses; the corresponding (-)-enantiomer did not serve as a substrate. This enantio-specificity for a PPO, a representative of a widespread class of enzymes, provides additional insight into their actual physiological roles that hitherto have been difficult to determine.
authors.affiliation: Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA.
authors.forename: Man-Ho
authors.initials: MH
authors.lastname: Cho
authors.forename: Syed G A
authors.initials: SG
authors.lastname: Moinuddin
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Helms
authors.forename: Shojiro
authors.initials: S
authors.lastname: Hishiyama
authors.forename: Dietmar
authors.initials: D
authors.lastname: Eichinger
authors.forename: Laurence B
authors.initials: LB
authors.lastname: Davin
authors.forename: Norman G
authors.initials: NG
authors.lastname: Lewis
mesh_terms: D000595:Amino Acid Sequence; D004156:Catechol Oxidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D032442:Larrea / Q000201:enzymology*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013237:Stereoisomerism
chemical_list: D018076:DNA, Complementary; C478129:(+)-Larreatricin hydroxylase, creosote bush; D004156:Catechol Oxidase