Get 20M+ Full-Text Papers For Less Than $1.50/day. Subscribe now for You or Your Team.

Learn More →

Structure and epimerase activity of anthocyanidin reductase from Vitis vinifera

Structure and epimerase activity of anthocyanidin reductase from Vitis vinifera Together with leucoanthocyanidin reductase, anthocyanidin reductase (ANR) is one of the two enzymes of the flavonoid‐biosynthesis pathway that produces the flavan‐3‐ol monomers required for the formation of proanthocyanidins or condensed tannins. It has been shown to catalyse the double reduction of anthocyanidins to form 2R,3R‐flavan‐3‐ols, which can be further transformed to the 2S,3R isomers by non‐enzymatic epimerization. ANR from grape (Vitis vinifera) was expressed in Escherichia coli and purified. Unexpectedly, RP‐HPLC, LC‐MS and NMR experiments clearly established that the enzyme produces a 50:50 mixture of 2,3‐cis and 2,3‐trans flavan‐3‐ols which have been identified by chiral chromatography to be 2S,3S‐ and 2S,3R‐flavan‐3‐ols, i.e. the naturally rare (+)‐epicatechin and (−)‐catechin, when cyanidin is used as the substrate of the reaction. The first three‐dimensional structure of ANR is described at a resolution of 2.2 Å and explains the inactivity of the enzyme in the presence of high salt concentrations. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Acta Crystallographica Section D Wiley

Loading next page...
 
/lp/wiley/structure-and-epimerase-activity-of-anthocyanidin-reductase-from-vitis-BOtGPat6qo

References (57)

Publisher
Wiley
Copyright
International Union of Crystallography, 2009
ISSN
1399-0047
eISSN
1399-0047
DOI
10.1107/S0907444909025013
pmid
19690377
Publisher site
See Article on Publisher Site

Abstract

Together with leucoanthocyanidin reductase, anthocyanidin reductase (ANR) is one of the two enzymes of the flavonoid‐biosynthesis pathway that produces the flavan‐3‐ol monomers required for the formation of proanthocyanidins or condensed tannins. It has been shown to catalyse the double reduction of anthocyanidins to form 2R,3R‐flavan‐3‐ols, which can be further transformed to the 2S,3R isomers by non‐enzymatic epimerization. ANR from grape (Vitis vinifera) was expressed in Escherichia coli and purified. Unexpectedly, RP‐HPLC, LC‐MS and NMR experiments clearly established that the enzyme produces a 50:50 mixture of 2,3‐cis and 2,3‐trans flavan‐3‐ols which have been identified by chiral chromatography to be 2S,3S‐ and 2S,3R‐flavan‐3‐ols, i.e. the naturally rare (+)‐epicatechin and (−)‐catechin, when cyanidin is used as the substrate of the reaction. The first three‐dimensional structure of ANR is described at a resolution of 2.2 Å and explains the inactivity of the enzyme in the presence of high salt concentrations.

Journal

Acta Crystallographica Section DWiley

Published: Sep 1, 2009

There are no references for this article.