title: Monoterpene alcohol metabolism: identification, purification, and characterization of two geraniol dehydrogenase isoenzymes from Polygonum minus leaves.
abstract: NADP(+)-dependent geraniol dehydrogenase (EC 1.1.1.183) is an enzyme that catalyzes the oxidation of geraniol to geranial. Stable, highly active cell-free extract was obtained from Polygonum minus leaves using polyvinylpolypyrrolidone, Amberlite XAD-4, glycerol, 2-mercaptoethanol, thiourea, and phenylmethylsulfonylfluoride in tricine-NaOH buffer (pH 7.5). The enzyme preparation was separated into two activity peaks, geraniol-DH I and II, by DEAE-Toyopearl 650M column chromatography at pH 7.5. Both isoenzymes were purified to homogeneity in three chromatographic steps. The geraniol-DH isoenzymes were similar in molecular mass, optimal temperature, and pH, but the isoelectric point, substrate specificity, and kinetic parameters were different. The K(m) values for geraniol of geraniol-DH I and II appeared to be 0.4 mM and 0.185 mM respectively. P. minus geraniol-DHs are unusual among geraniol-DHs in view of their thermal stability and optimal temperatures, and also their high specificity for allylic alcohols and NADP(+).
authors.affiliation: Institute of Systems Biology, Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia. maizom@ukm.my
authors.forename: Maizom
authors.initials: M
authors.lastname: Hassan
authors.forename: Nur Diyana
authors.initials: ND
authors.lastname: Maarof
authors.forename: Zainon Mohd
authors.initials: ZM
authors.lastname: Ali
authors.forename: Normah Mohd
authors.initials: NM
authors.lastname: Noor
authors.forename: Roohaida
authors.initials: R
authors.lastname: Othman
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Mori
mesh_terms: D000080462:Acyclic Monoterpenes; D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000302:isolation & purification; D055162:Biocatalysis; D004795:Enzyme Stability; D005990:Glycerol; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification; D007700:Kinetics; D008623:Mercaptoethanol; D008970:Molecular Weight; D039821:Monoterpenes / Q000737:chemistry*; D009249:NADP / Q000737:chemistry; D010664:Phenylmethylsulfonyl Fluoride; D018515:Plant Leaves / Q000737:chemistry / Q000201:enzymology*; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D028502:Polygonum / Q000737:chemistry / Q000201:enzymology*; D012997:Solvents; D013379:Substrate Specificity; D013696:Temperature; D013729:Terpenes / Q000737:chemistry*; D013890:Thiourea
chemical_list: D000080462:Acyclic Monoterpenes; D007527:Isoenzymes; D039821:Monoterpenes; D010940:Plant Proteins; D012997:Solvents; D013729:Terpenes; D009249:NADP; D010664:Phenylmethylsulfonyl Fluoride; D008623:Mercaptoethanol; D000429:Alcohol Oxidoreductases; D013890:Thiourea; C007836:geraniol; D005990:Glycerol; C007076:citral