Linked Life Data

12721858

Source:http://linkedlifedata.com/resource/pubmed/id/12721858

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2003-4-30
pubmed:abstractText
Arabidopsis thaliana Heynh. harbors UDP-glucose-dependent glucosyltransferase (UGT; EC 2.4.1.-) activities that are able to glucosylate xenobiotic substrates as a crucial step in their detoxification, similar to other plants. However, it has remained elusive whether side-activities of UGTs acting on endogenous substrates could account for that property. Therefore, seven recombinantly expressed A. thaliana enzymes were tested using the phytotoxic xenobiotic model compound 2,4,5-trichlorophenol (TCP) as a substrate. The enzymes were selected from the large Arabidopsis UGT gene family because their previously identified putative endogenous substrates comprised both carboxylic acid, and phenolic and aliphatic hydroxyl moieties as biochemical targets. In addition, UGT75D1, which was shown to accept the endogenous flavonoid kaempferol as a substrate, was included. All enzymes tested, except the sterol-conjugating UGT80A2, glucosylated TCP as a parallel activity. The K(m) values for TCP ranged from 0.059 to 1.25 mM. When tested at saturating concentrations of the native substrates the glucosylation of TCP by the glucose-ester-forming UGT84A1 and UGT84A2 was suppressed by p-coumaric acid and sinapic acid, respectively. In contrast, the activities of UGT72E2 and UGT75D1 toward their phenolic native substrates and the xenobiotic TCP were mutually inhibited. TCP was a competitive inhibitor of sinapyl alcohol glucosylation by UGT72E2. These overlapping in vitro activities suggest cross-talk between the detoxification of xenobiotics and endogenous metabolism at the biochemical level, depending on the presence of competing substrates and enzymes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/2,4,5-trichlorophenol, http://linkedlifedata.com/resource/pubmed/chemical/4-coumaric acid, http://linkedlifedata.com/resource/pubmed/chemical/Arabidopsis Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Chlorophenols, http://linkedlifedata.com/resource/pubmed/chemical/Coumaric Acids, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Flavonoids, http://linkedlifedata.com/resource/pubmed/chemical/Glucosyltransferases, http://linkedlifedata.com/resource/pubmed/chemical/Kaempferols, http://linkedlifedata.com/resource/pubmed/chemical/Xenobiotics, http://linkedlifedata.com/resource/pubmed/chemical/kaempferol, http://linkedlifedata.com/resource/pubmed/chemical/sinapinic acid
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0032-0935
pubmed:author
pubmed:issnType
Print
pubmed:volume
217
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
138-46
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Arabidopsis glucosyltransferases with activities toward both endogenous and xenobiotic substrates.
pubmed:affiliation
Institute of Biochemical Plant Pathology, GSF-National Research Center for Environment and Health, 85764, Neuherberg, Germany.
pubmed:publicationType
Journal Article