Stereospecificity of hydrogen transfer by NADP-linked acyclic monoterpene primary alcohol dehydrogenase

Monoterpene Alcohol Metabolism: Identification, Purification, and Characterization of Two Geraniol Dehydrogenase Isoenzymes fromPolygonum minusLeaves

“…The substrate specificities of P. minus geraniol-DH I and II also showed similarity to other alcohol dehydrogenases, in which saturation of the double bonds and increasing the chain length severely reduces substrate binding. [9][10][11]16,32,33,35) Furthermore, neither P. minus geraniol-DH exhibited activity against aliphatic alcohols, indicating that both of the enzymes are specific for substrates containing allylic double bonds. This suggests that P. minus geraniol-DHs can recognize allylic alcohols with carbon chain lengths between 9 and 10 and even a small difference in the structure of the substrate.…”

“…28) In addition, Ipomoea batatas farnesol dehydrogenase, 27) N. racemosa acyclic monoterpene primary alcohol dehydrogenase, 29) and the alcohol dehydrogenases of Triticum turgidum, 26) Vitis vinifera, 30) and cultured rice cells 31) are all dimers of 37-58 kDa. On the other hand, geraniol-DH from the astigmatid mite 16) and acyclic monoterpene primary alcohol dehydrogenase from Rauwolfia serpentina 32) have been reported to act as monomers.…”

“…The isoelectric points of P. minus geraniolDHs were different from those of other plant alcohol dehydrogenases. The acyclic monoterpene primary alcohol dehydrogenase from R. serpentina 32) and the alcohol dehydrogenases of T. turgidum, 26) V. vinifera, 30) and cultured rice cells 31) were weak acidic proteins having estimated isoelectric points between 5.4-5.76.…”

“…8,9) NAD þ was ineffective as a cofactor for both P. minus geraniol-DHs, suggesting that both isoenzymes are NADP þ -dependent alcohol dehydrogenases, similarly to other plant geraniol-DHs [8][9][10][11] and plant terpene alcohol dehydrogenases. 27,29,32) On the other hand, the geraniol-DH from Carpoglyphus lactis had an absolute requirement of NAD þ as cofactor. 16) Both NAD þ and NADP þ can be utilized as cofactors for M. piperita isopiperitenol dehydrogenase 22) and S. officinalis borneol dehydrogenase.…”

The biosynthesis of C5–C20terpenoid compounds

“…A primary alcohol dehydrogenase involved in the biosynthesis of iridoids and the non-tryptamine portion of terpenoid indole alkaloids has been isolated from cell cultures of Rauwo@a serpentina and purified to homogeneity, following the discovery of suitable conditions which stabilize the enzyme. 67 The enzyme appears to function in the reversible dehydrogenation of 8-hydroxygeraniol (57) to 8-oxogeraniol (58) or to 8-hydroxygeranial (59), and the further oxidation of these compounds to 8-oxogeranial (60), the direct precursor of iridodial (61) (Scheme 12). The enzyme required NADP' as cofactor, and would accept a variety of branched-chain allylic primary alcohols as substrates.…”