Partial purification and characterisation of a 2,4,5-trichlorophenol detoxifying O-glucosyltransferase from wheat

An enzyme preparation with UDP-glucose-dependcnt O-glucosyltransferase (OGT; EC 2.4.1.-) activity toward chlorophenol has been purified 215-fold from wheat shoots. The OGT co-purified with the major extractable glucosylating activity toward the flavonol quercetin and was characterised as a monomeric 53 kDa protein. Among the xenobiotic phenols tested, the purified enzyme preparation showed at least a 10-fold preference for 2,4,5-trichlorophenol. When assayed with flavonoids, the OGT was active toward flavonols and coumestrol, showing a clear preference for 3-hydroxy flavone when incubated with a range of monohydroxylated flavonoids. It was concluded that the major 2.4,5-trichlorophenol-detoxifying OGT in wheat shoots is most probably a flavonol-3-O-glucosytransferase. (C) 2003 Elsevier Ltd. All rights reserved.