title: Further characterization and regulation of malonyl-coenzyme A: flavonoid glucoside malonyltransferases from parsley cell suspension cultures.
abstract: Two malonyltransferases, malonyl-CoA:flavone/flavonol 7-O-glucoside malonyltransferase and malonyl-CoA:flavonol 3-O-glucoside malonyltransferase, were purified to apparent homogeneity from uv-irradiated parsley cell cultures. Both purified enzymes appear to be specific for flavonoid glycosides. Additional malonyltransferases, active toward several phenol glucosides other than flavonoids, were present in partially purified 7-O-glucoside malonyltransferase preparations. Antibodies raised against the purified 3-O-glucoside malonyltransferase did not inhibit the activity of the 7-O-glucoside malonyltransferase over a wide antibody concentration range. Determination of the rate of synthesis in vivo of the 3-O-glucoside malonyltransferase after ultraviolet light-pulse induction of parsley cells revealed two maxima at 6 and 30 h, respectively. These results indicate that the induced changes in 3-O-glucoside malonyltransferase activity were the consequence of either a repeated change in the rate of synthesis of one enzyme species or changes in the synthesis rates of more than one enzyme species.
mesh_terms: D000217:Acyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D002478:Cells, Cultured; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D010944:Plants / Q000201:enzymology* / Q000528:radiation effects; D013379:Substrate Specificity
chemical_list: D000217:Acyltransferases; C030916:malonyl-CoA-flavone-flavonol-7-O-glycoside malonyltransferase