(+)-Larreatricin hydroxylase, an enantio-specific polyphenol oxidase from the creosote bush (Larrea tridentata).
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.
Cho
Man-Ho
MH
Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA.
Moinuddin
Syed G A
SG
Helms
Gregory L
GL
Hishiyama
Shojiro
S
Eichinger
Dietmar
D
Davin
Laurence B
LB
Lewis
Norman G
NG
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
D018076:DNA, Complementary; C478129:(+)-Larreatricin hydroxylase, creosote bush; D004156:Catechol Oxidase