Purification and Characterization of a O-Methyltransferase Capable of Methylating 2-Hydroxy-3-alkylpyrazine from Vitis vinifera L. (cv. Cabernet Sauvignon)

Hashizume, Katsumi; Tozawa, Kazuyuki; Hiraga, Yoshikazu; Aramaki, Isao

doi:10.1271/bbb.65.2213

Cited by 29 publications

(38 citation statements)

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“…Subsequently, an enzyme with such activity was purified from grape and 20 amino acids of N-terminal sequence of the protein was obtained (Hashizume et al 2001b). A search of grapevine EST sequences revealed a Cabernet Sauvignon cDNA clone encoding a protein with a 100% match to the N-terminal amino acid sequence of the purified protein ( Fig.…”

Section: Resultsmentioning

confidence: 99%

“…It has been shown that Cabernet Sauvignon grapes contain an enzyme capable of the methylation of HP (Hashizume et al 2001a) and an OMT enzyme with this activity was purified and the N-terminus partially sequenced (Hashizume et al 2001b). These authors also found that the levels of HP were between 2 and 20-fold Proposed pathway for the biosynthesis of 3-isopropyl-2-methoxypyrazine (IPMP) and 3-isobutyl-2-methoxypyrazine (IBMP) from the amino acids valine and leucine, respectively.…”

Section: Introductionmentioning

confidence: 99%

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Two O-methyltransferases involved in the biosynthesis of methoxypyrazines: grape-derived aroma compounds important to wine flavour

et al. 2010

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Methoxypyrazines (MPs) are volatile, grape-derived aroma compounds that contribute to the distinct herbaceous characters of some wines. Although the full pathway leading to MP production has not been elucidated, there is strong evidence that the final step involves the methylation of non-volatile hydroxypyrazine (HP) precursors. Two cDNA encoding O-methyltransferases (OMTs) that have homology to an enzyme previously purified and shown to catalyse the methylation of HPs were isolated from Cabernet Sauvignon. Recombinant protein from the cDNAs (VvOMT1 and VvOMT2) was produced in E. coli and activity assays demonstrated that both encode OMTs able to methylate HPs to produce MPs, however both showed greatest activity against the flavonol quercetin. VvOMT1 has higher catalytic activity against isobutyl hydroxypyrazine compared to isopropyl hydroxypyrazine, whereas the converse is true for VvOMT2. The timing of the expression of VvOMT1 in the skin and the flesh of developing Cabernet Sauvignon grape berries was associated with the period of MP accumulation in these tissues, while VvOMT2 expression was greatest in roots, which were found to contain high levels of MPs. The MP composition of these tissues also reflects the relative levels of expression of these genes and their substrate preference. The identification of genes responsible for MP production in grapevine will help in understanding the effect of different viticultural and environmental factors on MP accumulation.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Two O-methyltransferases involved in the biosynthesis of methoxypyrazines: grape-derived aroma compounds important to wine flavour

et al. 2010

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“…As a first approach, a CS 3 RGM progeny has been used to analyze the genetic bases of IBMP biosynthesis in leaves, allowing the detection of five significant QTLs, explaining 41% of the variance in IBMP content. The last step of MP biosynthesis involves an O-methylation reaction, and candidate OMTs have been proposed to catalyze this reaction (Murray and Whitfield, 1975;Hashizume et al, 2001b;Dunlevy et al, 2010). Therefore, we first focused on candidate OMTs present between the markers flanking the detected QTLs.…”

Section: Vvomt3 and Vvomt4 Gene Expression Profiles Mirror Ibmp Accummentioning

confidence: 99%

“…They all start by the addition of an adicarbonyl on a branched amino acid (Leu for IBMP, Val for IPMP) to form a 2-hydroxy-3-alkylpyrazine, which is subsequently transformed into the corresponding MP, by a methoxylation reaction (Murray and Whitfield 1975;Gallois et al, 1988). While the initial addition step remains to be demonstrated in plants, an S-adenosyl-L-Met (SAM)-dependent O-methyltransferase (OMT), capable of converting 2-hydroxy-3-isobutylpyrazine (IBHP) into IBMP, has been detected in CS shoots, partially purified and sequenced (Hashizume et al, 2001a(Hashizume et al, , 2001b; Fig. 1).…”

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confidence: 99%

Genetic Analysis of the Biosynthesis of 2-Methoxy-3-Isobutylpyrazine, a Major Grape-Derived Aroma Compound Impacting Wine Quality

et al. 2013

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Methoxypyrazines (MPs) are strongly odorant volatile molecules with vegetable-like fragrances that are widespread in plants. Some grapevine (Vitis vinifera) varieties accumulate significant amounts of MPs, including 2-methoxy-3-isobutylpyrazine (IBMP), which is the major MP in grape berries. MPs are of particular importance in white Sauvignon Blanc wines. The typicality of these wines relies on a fine balance between the pea pod, capsicum character of MPs and the passion fruit/grapefruit character due to volatile thiols. Although MPs play a crucial role in Sauvignon varietal aromas, excessive concentrations of these powerful odorants alter wine quality and reduce consumer acceptance, particularly in red wines. The last step of IBMP biosynthesis has been proposed to involve the methoxylation of the nonvolatile precursor 2-hydroxy-3-isobutylpyrazine to give rise to the highly volatile IBMP. In this work, we have used a quantitative trait loci approach to investigate the genetic bases of IBMP biosynthesis. This has led to the identification of two previously uncharacterized S-adenosyl-methionine-dependent O-methyltransferase genes, termed VvOMT3 and VvOMT4. Functional characterization of these two O-methyltransferases showed that the VvOMT3 protein was highly specific and efficient for 2-hydroxy-3-isobutylpyrazine methylation. Based on its differential expression in high- and low-MP-producing grapevine varieties, we propose that VvOMT3 is a key gene for IBMP biosynthesis in grapevine.

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“…20) The final methylation reaction to hydroxypyrazine with S-adenocyl-L-methionine has recently been demonstrated by Hashizume et al as a model reaction catalyzed by Omethyltransferase isolated from young grapevine shoots. 21) Based on the previous studies concerning the formation mechanisms for the other key aroma compounds, they all seem to have been generated from amino acids, sugars, and phenolic acids by a thermal treatment.…”

Section: Resultsmentioning

confidence: 99%

Key Aroma Compounds in Roasted In-shell Peanuts

Kaneko¹,

Sakai²,

Kumazawa³

et al. 2013

Bioscience, Biotechnology, and Biochemistry

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Purification and Characterization of a O-Methyltransferase Capable of Methylating 2-Hydroxy-3-alkylpyrazine from Vitis vinifera L. (cv. Cabernet Sauvignon)

Cited by 29 publications

References 1 publication

Two O-methyltransferases involved in the biosynthesis of methoxypyrazines: grape-derived aroma compounds important to wine flavour

Two O-methyltransferases involved in the biosynthesis of methoxypyrazines: grape-derived aroma compounds important to wine flavour

Genetic Analysis of the Biosynthesis of 2-Methoxy-3-Isobutylpyrazine, a Major Grape-Derived Aroma Compound Impacting Wine Quality

Key Aroma Compounds in Roasted In-shell Peanuts

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