Abstract
Characterization of anthocyanin acyl transferases (AATs) using acyl-CoA molecules as acyl-donors have been progressed and the genes encoded in their enzymes have been identified. Recently, the enzyme protein transferring aromatic moieties using 1-O-β-acylglucoses as acyl-donors, acyl glucoside dependent acyl transferase (AGDAT), were purified from petals of Clitoria ternatea and a cDNA encoded its enzyme activity was isolated. We established an anthocyanin-synthesizing cultured-cell line of carrot suspension cultures in which cells produced and accumulated cyanidin 3-[Xyl-(sinapoyl-Glc)-Gal] as a main pigment. In the crude protein extract prepared from the cells, the AGDAT activity was detected using sinapoyl-glucoside as an acyl-donor. In order to synthesize several molecular species of glucosides conjugated with phenylpropanoid derivatives, a recombinant UDP-glucose:phenylpropanoid glucosyltransferase was prepared from E. coli harboring a cDNA isolated from petals of Gomphrena globosa. Using the several species of phenylpropanoid glucosides as acyl-donors, substrate specificity of AGDAT in carrot was characterized.
