title: Anthocyanin 5-aromatic acyltransferase from Gentiana triflora. Purification, characterization and its role in anthocyanin biosynthesis.
abstract: Acylation with hydroxycinnamic acids stabilizes anthocyanins and makes their colour bluer (bathochromic shift). We purified to homogeneity one acylation enzyme, hydroxycinnamoyl-CoA:anthocyanidin 3,5-diglucoside 5-O-glucoside-6"'-O-hydroxycinnamoyltransferase, from blue petals of Gentiana triflora. It is a single polypeptide protein of 52 kDa with a pI of 4.6. It catalyzes the transfer of the p-coumaric acid and caffeic acid from their CoA esters to the 5-glucosyl moiety of anthocyanidin 3,5-diglucosides but could not use malonyl-CoA as an acyl donor. Neither anthocyanidin 3-monoglucoside nor anthocyanins aromatically acylated at the 3-glucosyl moiety could be acylated by this enzyme. Aromatic acylation of anthocyanidin 3,5-diglucoside by this enzyme caused a bathochromic shift and increased pigment stability in neutral to weakly basic pH. Other anthocyanins from the petals of G. triflora were isolated and their structures were determined by fast-atom-bombardment MS and NMR. The biosynthetic pathway of gentiodelphin, a diacylated anthocyanin accumulating in G. triflora petals, is proposed on the basis of these results.
authors.affiliation: Institute for Fundamental Research, Suntory Ltd, Osaka, Japan. src08807@nisiq.net
authors.forename: H
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Fukui
authors.forename: M
authors.initials: M
authors.lastname: Nakao
authors.forename: T
authors.initials: T
authors.lastname: Ashikari
authors.forename: T
authors.initials: T
authors.lastname: Kusumi
mesh_terms: D000215:Acylation; D000217:Acyltransferases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D000872:Anthocyanins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D007526:Isoelectric Point; D015394:Molecular Structure; D008970:Molecular Weight; D010944:Plants / Q000201:enzymology* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D000872:Anthocyanins; D000217:Acyltransferases; C109044:hydroxycinnamoyl-CoA anthocyanidin 3,5-diglucoside 5-O-glucoside-6'''-O-hydroxycinnamoyltransferase