title: Effect of the minor ABA metabolite 7'-hydroxy-ABA on Arabidopsis ABA 8'-hydroxylase CYP707A3.
abstract: To examine the effect of the minor abscisic acid (ABA) metabolite 7'-hydroxy-ABA on Arabidopsis ABA 8'-hydroxylase (CYP707A3), we developed a novel and facile, four-step synthesis of 7'-hydroxy-ABA from alpha-ionone. Structural analogues of 7'-hydroxy-ABA, 1'-deoxy-7'-hydroxy-ABA, and 7'-oxo-ABA were also synthesized to evaluate the role of the 7'-hydroxyl group on binding to the enzyme. The result of enzyme inhibition assay suggests that the local polarity at C-7', neither steric bulkiness nor overall molecular hydrophilicity, would be the major reason why (+)-7'-hydroxy-ABA is not a potent inhibitor of CYP707A3.
authors.affiliation: Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Shimomura
authors.forename: Hideo
authors.initials: H
authors.lastname: Etoh
authors.forename: Masaharu
authors.initials: M
authors.lastname: Mizutani
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hirai
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Todoroki
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry*; D001665:Binding Sites; D002384:Catalysis; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry*; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D006899:Mixed Function Oxygenases / Q000737:chemistry*; D008956:Models, Chemical; D008968:Molecular Conformation; D010100:Oxygen / Q000737:chemistry; D018521:Plant Physiological Phenomena / Q000187:drug effects; D010940:Plant Proteins; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; D004791:Enzyme Inhibitors; D010940:Plant Proteins; D000040:Abscisic Acid; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C107203:abscisic acid 8'-hydroxylase; D010100:Oxygen