Biosynthesis of methoxypyrazines: Elucidating the structural/functional relationship of two vitis vinifera O-methyltransferases capable of catalyzing the putative final step of the biosynthesis of 3-alkyl-2-methoxypyrazine

José G. Vallarino, Xaviera A. López-Cortés, Jake D. Dunlevy, Paul K. Boss, Fernando D. González-Nilo, Yerko M. Moreno

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

3-Alkyl-2-methoxypyrazines (MPs) are an important food constituent and have been associated with detrimental herbaceous flavors in red wines by consumers and the wine industry. The Vitis vinifera genes O-methyltransferase 1 and 2 (VvOMT1 and VvOMT2) have been isolated in the grapevine cultivar Carmenere. These genes encode S-adenosyl-l-methionine (SAM)-dependent O-methyltransferases, which have the ability to methylate 3-alkyl-2-hydroxypyrazines (HPs)-the putative final step in MPs production. Atomic studies were performed in order to explain the differences in these VvOMT activities through their structural/functional relationship in MPs biosynthesis. Differences in enthalpy energy observed between the proteins may be due to changes of equivalent residues in the active sites of VvOMT1 (F319, L322) and VvOMT2 (L319, V322). However, docking simulations and QM/MM analyses described how residues H272 and M182 could explain the main functional differentiation observed between VvOMT1 and VvOMT2 through steric impediment, which limits the formation of the transition state in enzymes encoded by VvOMT2. Therefore, this finding could explain the decreasing catalytic efficiency observed for VvOMT2.

Original languageEnglish
Pages (from-to)7310-7316
Number of pages7
JournalJournal of Agricultural and Food Chemistry
Volume59
Issue number13
DOIs
Publication statusPublished - 13 Jul 2011

Keywords

  • docking simulation
  • flavor
  • methoxypyrazines
  • methyltransferases
  • QM/MM
  • Vitis vinifera
  • wine

ASJC Scopus subject areas

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

Fingerprint

Dive into the research topics of 'Biosynthesis of methoxypyrazines: Elucidating the structural/functional relationship of two vitis vinifera O-methyltransferases capable of catalyzing the putative final step of the biosynthesis of 3-alkyl-2-methoxypyrazine'. Together they form a unique fingerprint.

Cite this