Affiliations: Department of Chemistry, College of Natural Sciences,
Chung-Ang University, Seoul, Republic of Korea
Note: [] Address for correspondence: Professor Kwang-Hoon Kong,
Department of Chemistry, College of Natural Sciences, Chung-Ang University,
221, Huksuk-Dong, Dongjak-Ku, Seoul 156-756, Republic of Korea. Tel.: +82 2
8205205; Fax: +82 2 8254736; E-mail: khkong@cau.ac.kr
Abstract: To gain further insight into herbicide detoxification, we studied
the herbicide activity and specificity toward glutathione
S-transferases from human and rice. In this study, the genes
of the plant specific phi and tau class GST enzymes from Oryza sativa
(OsGST) and human pi class GST enzyme (hGSTP1-1) were cloned and
expressed in Escherichia coli with the pET and pKK vector systems,
respectively. The gene products were purified to homogeneity by GSH Sepharose
affinity column chromatography. The herbicide specificity of the enzymes was
investigated by enzyme-catalyzed conjugation of GSH with chloroacetanilide,
diphenylether and chloro-s-triazine herbicides. The hGSTP1-1
showed very high specific activity toward atrazine. On the other hand, the phi
class OsGST enzymes showed high specific activity toward
chloroacetanilide herbicides, acetochlor, alachlor and metolachlor. The tau
class GST enzymes displayed remarkable activity toward the diphenylether
herbicide, fluorodifen. From these results, we conclude that the phi and the
tau class GST enzymes show herbicide specificities and also they play an
important role in the detoxification reaction of plant toward herbicides.
Keywords: Glutathione S-transferase, herbicide detoxification, herbicide specificity, Oryza sativa GST, phi class GST, rice, tau class GST
Journal: BioFactors, vol. 30, no. 4, pp. 281-287, 2007
