Vanillin formation from ferulic acid in Vanilla planifolia is catalysed by a single enzyme

TY - JOUR

T1 - Vanillin formation from ferulic acid in Vanilla planifolia is catalysed by a single enzyme

AU - Gallage, Nethaji Janeshawari

AU - Hansen, Esben Halkjær

AU - Kannangara, Rubini Maya

AU - Olsen, Carl Erik

AU - Motawie, Mohammed Saddik

AU - Jørgensen, Kirsten

AU - Holme, Inger

AU - Hebelstrup, Kim

AU - Grisoni, Michel

AU - Møller, Birger Lindberg

N1 - OA

PY - 2014/6/19

Y1 - 2014/6/19

N2 - Vanillin is a popular and valuable flavour compound. It is the key constituent of the natural vanilla flavour obtained from cured vanilla pods. Here we show that a single hydratase/lyase type enzyme designated vanillin synthase (VpVAN) catalyses direct conversion of ferulic acid and its glucoside into vanillin and its glucoside, respectively. The enzyme shows high sequence similarity to cysteine proteinases and is specific to the substitution pattern at the aromatic ring and does not metabolize caffeic acid and p-coumaric acid as demonstrated by coupled transcription/translation assays. VpVAN localizes to the inner part of the vanilla pod and high transcript levels are found in single cells located a few cell layers from the inner epidermis. Transient expression of VpVAN in tobacco and stable expression in barley in combination with the action of endogenous alcohol dehydrogenases and UDP-glucosyltransferases result in vanillyl alcohol glucoside formation from endogenous ferulic acid. A gene encoding an enzyme showing 71% sequence identity to VpVAN was identified in another vanillin-producing plant species Glechoma hederacea and was also shown to be a vanillin synthase as demonstrated by transient expression in tobacco.

AB - Vanillin is a popular and valuable flavour compound. It is the key constituent of the natural vanilla flavour obtained from cured vanilla pods. Here we show that a single hydratase/lyase type enzyme designated vanillin synthase (VpVAN) catalyses direct conversion of ferulic acid and its glucoside into vanillin and its glucoside, respectively. The enzyme shows high sequence similarity to cysteine proteinases and is specific to the substitution pattern at the aromatic ring and does not metabolize caffeic acid and p-coumaric acid as demonstrated by coupled transcription/translation assays. VpVAN localizes to the inner part of the vanilla pod and high transcript levels are found in single cells located a few cell layers from the inner epidermis. Transient expression of VpVAN in tobacco and stable expression in barley in combination with the action of endogenous alcohol dehydrogenases and UDP-glucosyltransferases result in vanillyl alcohol glucoside formation from endogenous ferulic acid. A gene encoding an enzyme showing 71% sequence identity to VpVAN was identified in another vanillin-producing plant species Glechoma hederacea and was also shown to be a vanillin synthase as demonstrated by transient expression in tobacco.

U2 - 10.1038/ncomms5037

DO - 10.1038/ncomms5037

M3 - Journal article

C2 - 24941968

SN - 2041-1723

VL - 5

JO - Nature Communications

JF - Nature Communications

IS - 6

M1 - 4037

ER -