Cummins_2007_Phytochemistry_68_811

Reference

Title : Structure activity studies with xenobiotic substrates using carboxylesterases isolated from Arabidopsis thaliana - Cummins_2007_Phytochemistry_68_811
Author(s) : Cummins I , Landrum M , Steel PG , Edwards R
Ref : Phytochemistry , 68 :811 , 2007
Abstract :

Carboxylesterases (CXEs) catalyse the hydrolysis of xenobiotics and natural products radically altering their biological activities. Whereas the substrate selectivity of animal CXEs, such as porcine liver esterase (PLE) have been well studied, the respective enzymes in plants have yet to be defined and their activities determined. Using Arabidopsis thaliana (At) as a source, five representative members of the alpha/beta hydrolase AtCXE family of proteins have been cloned, expressed and the purified recombinant proteins assayed for esterase activity with xenobiotic substrates. Two members, AtCXE5 and AtCXE18 were found to be active carboxylesterases, though AtCXE5 proved to be highly unstable as a soluble protein. AtCXE18 and the previously characterised S-formylglutathione hydrolase from Arabidopsis (AtSFGH) were assayed against a series of esters based on methylumbelliferone in which the acyl moiety was varied with respect to size and conformation. The same series was used to assay crude esterase preparation from Arabidopsis plants and the results compared with those obtained with the commonly used PLE. With straight chain esters, AtCXE18 behaved like PLE, but the Arabidopsis hydrolases proved less tolerant of branched chain acyl components than the mammalian enzyme. While none of the enzyme preparations accurately reflected all the activities determined with crude Arabidopsis protein extracts, the plant enzymes proved more useful than PLE in predicting the hydrolysis of the more sterically constrained esters.

PubMedSearch : Cummins_2007_Phytochemistry_68_811
PubMedID: 17270225
Gene_locus related to this paper: arath-AT5G62180

Related information

Gene_locus arath-AT5G62180

Citations formats

Cummins I, Landrum M, Steel PG, Edwards R (2007)
Structure activity studies with xenobiotic substrates using carboxylesterases isolated from Arabidopsis thaliana
Phytochemistry 68 :811

Cummins I, Landrum M, Steel PG, Edwards R (2007)
Phytochemistry 68 :811