Publications

• Geraniol dehydrogenase activity related to aroma formation in ginger (Zingiber officinale Roscoe).

  Sekiwa-Iijima Y., Aizawa Y., Kubota K.

  Geranial is one of the potent odor compounds in fresh ginger. To clarify the generation of geranial in ginger, the alcohol dehydrogenase activity was measured in a crude enzymatic system of ginger. This enzyme solution was found to contain geraniol dehydrogenase (GeDH) specifically acting on geran ... >> More

  Geranial is one of the potent odor compounds in fresh ginger. To clarify the generation of geranial in ginger, the alcohol dehydrogenase activity was measured in a crude enzymatic system of ginger. This enzyme solution was found to contain geraniol dehydrogenase (GeDH) specifically acting on geraniol as a substrate with NADP as a coenzyme. Geranial generation and GeDH activity were investigated for different maturity stages and storage periods of ginger. Both were at maximum levels from just after harvesting to initial storage. The GeDH activity subsequently dropped, and the generation of geranial also stopped. These results suggest that the GeDH activity in ginger is related to the generation of geranial. << Less

  J Agric Food Chem 49:5902-5906(2001) [PubMed] [EuropePMC]

• Geraniol dehydrogenase, the key enzyme in biosynthesis of the alarm pheromone, from the astigmatid mite Carpoglyphus lactis (Acari: Carpoglyphidae).

  Noge K., Kato M., Mori N., Kataoka M., Tanaka C., Yamasue Y., Nishida R., Kuwahara Y.

  Geraniol dehydrogenase (GeDH), which plays an important role in the biosynthesis of neral, an alarm pheromone, was purified from the astigmatid mite Carpoglyphus lactis. The enzyme was obtained in an apparently homogeneous and active form after 1879-fold purification through seven steps of chromat ... >> More

  Geraniol dehydrogenase (GeDH), which plays an important role in the biosynthesis of neral, an alarm pheromone, was purified from the astigmatid mite Carpoglyphus lactis. The enzyme was obtained in an apparently homogeneous and active form after 1879-fold purification through seven steps of chromatography. Car. lactis GeDH was determined to be a monomer in its active form with a relative molecular mass of 42 800, which is a unique subunit structure in comparison with already established alcohol dehydrogenases. Car. lactis GeDH oxidized geraniol into geranial in the presence of NAD+. NADP+ was ineffective as a cofactor, suggesting that Car. lactis GeDH is an NAD+-dependent alcohol dehydrogenase. The optimal pH and temperature for geraniol oxidation were determined to be pH 9.0 and 25 degrees C, respectively. The Km values for geraniol and NAD+ were 51.0 microm and 59.5 microm, respectively. Car. lactis GeDH was shown to selectively oxidize geraniol, whereas its geometrical isomer, nerol, was inert as a substrate. The high specificity for geraniol suggests that Car. lactis GeDH specializes in the alarm pheromone biosynthesis of Car. lactis. Car. lactis GeDH is composed of 378 amino acids. Structurally, Car. lactis GeDH showed homology with zinc-dependent alcohol dehydrogenases found in mammals and a mosquito (36.6-37.6% identical), and the enzyme was considered to be a member of the medium-chain dehydrogenase/reductase family, in view of the highly conserved sequences of zinc-binding and NAD+-binding sites. Phylogenetic analyses indicate that Car. lactis GeDH could be categorized as a new class, different from other established alcohol dehydrogenases. << Less

  FEBS J. 275:2807-2817(2008) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Analysis of the enzymatic formation of citral in the glands of sweet basil.

  Iijima Y., Wang G., Fridman E., Pichersky E.

  Basil glands of the Sweet Dani cultivar contain high levels of citral, a mixture of geranial and its cis-isomer neral, as well as low levels of geraniol and nerol. We have previously reported the identification of a cDNA from Sweet Dani that encodes an enzyme responsible for the formation of geran ... >> More

  Basil glands of the Sweet Dani cultivar contain high levels of citral, a mixture of geranial and its cis-isomer neral, as well as low levels of geraniol and nerol. We have previously reported the identification of a cDNA from Sweet Dani that encodes an enzyme responsible for the formation of geraniol from geranyl diphosphate in the glands, and that these glands cannot synthesize nerol directly from geranyl diphosphate. Here, we report the identification of two basil cDNAs encoding NADP+-dependent dehydrogenases that can use geraniol as the substrate. One cDNA, designated CAD1, represents a gene whose expression is highly specific to gland cells of all three basil cultivars examined, regardless of their citral content, and encodes an enzyme with high sequence similarity to known cinnamyl alcohol dehydrogenases (CADs). The enzyme encoded by CAD1 reversibly oxidizes geraniol to produce geranial (which reversibly isomerizes to neral via keto-enol tautomerization) at half the efficiency compared with its activity with cinnamyl alcohol. CAD1 does not use nerol and neral as substrates. A second cDNA, designated GEDH1, encodes an enzyme with sequence similarity to CAD1 that is capable of reversibly oxidizing geraniol and nerol in equal efficiency, and prolonged incubation of geraniol with GEDH1 in vitro produces not only geranial and neral, but also nerol. GEDH1 is also active, although at a lower efficiency, with cinnamyl alcohol. However, GEDH1 is expressed at low levels in glands of all cultivars compared with its expression in leaves. These and additional data presented indicate that basil glands may contain additional dehydrogenases capable of oxidizing geraniol. << Less

  Arch. Biochem. Biophys. 448:141-149(2006) [PubMed] [EuropePMC]