Einsatz der hochleistungsflüssigkeitschromatographie zur bestimmung der uridine-5′-diphosphoglucose:phenol-β-D-glucosyltransferase-aktivität in vitro mit partiell gereinigtem enzym aus pflanzen von beta vulgaris ssp. Rapacea var. altissima döll

Stölzel, G.; Pommer, U.; Hartung, J.; Gräser, H.

doi:10.1016/s0021-9673(00)91575-9

Cited by 3 publications

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Phenol β‐glucosyltransferase and β‐glucosidase activities in the tobacco hornworm larva Manduca sexta (L.): Properties and tissue localization

Ahmad

Hopkins

1992

Arch Insect Biochem Physiol

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Phenol p-glucosyltransferase (PGT; EC 2.4.1.35) was studied in feeding fifth stadium larvae of the tobacco hornworm, Manduca sexta, using reversed-phase HPLC with absorbance detection to separate and quantify both the model substrate, p-nitrophenol (PNP), and the product, p-nitrophenyl f3-D-glucopyranoside (PNP-Clc). About 90% of total PGT activity in tissue homogenates was associated with the particulate fraction (1 5,00(%), with the remainder in the microsomal fraction. PGT activity was observed in all tissues, with highest activities in the labial gland and fat body. Appreciable activity occurred in rnidgut and hindgut tissue but none was found in hernolymph. PGT activity was also observed in eggs and larval fat body at different times during development. Activity was optimal at pH 7.5-9 and was highest with UDP-Glc as a glucose donor. However, appreciable PCT activity was observed with dTDP-Clc or GDP-Glc in place of UDP-Glc. The divalent cations Ca2+, Co2+, Mg", and Mn2' stimulated activity, whereas Zn2+ and Hg2+, as well as pretreatment with the detergent Triton X-100, were inhibitory. Endogenous P-glucosidase in the PGT-enriched fractions, especially from the midgut, antagonized the pglucosylation process, and interference was minimized with higher pH and the addition of D-gluconic acid lactone to the incubation mixtures. The possible role of transglucosylation in the detoxication of phenolic xenobiotics and biotransformation of endogenous phenolic compounds in insects i s discussed. Comparisons of PCT with some glycosyltransferases involved in endogenous and xenobiotic conjugation in insects and other organisms are reviewed. Q 1992 Wiley-Liss, Inc.

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