Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (9)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Satoh, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Satoh, K.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1995 Oxford University Press

research-article

The high non-enzymatic conjugation rates of some glutathione S-transferase (GST) substrates at high glutathione concentrations

Kimihiko Satoh

Second Department of Biochemistry, Hirosaki University, School of Medicine 5 Zaifu-Cho, Hirosaki, Hirosaki 036, Japan

Enzymatic properties of five human glutathione S-transferases (GSTs) and non-enzymatic conjugation rates of GST substrates were examined as a function of glutathione (GSH) concentration and pH. GSTP1–1 showed a broad substrate specificity with both low and high GSH (10 mM) concentrations at pH 7.0, and the inhibitor insensitivity was then prominent. Among the GST substrates tested, ethacrynic acid, p-nitrophenylacetate, 1-chloro-2, 4-dinitro-benzene and trans-4-phenyl-3-buten-2-one conjugated non-enzymatically with half-times of 0.39, 3.1, 9.4 and 10.0 min respectively at 10 mM GSH, pH 7.0 and 35°C. The halftime for acrolein estimated by extrapolation was ~0.5 s. While the enzymatic reaction rates were independent of GSH at concentrations larger than Km values according to Michaelis—Menten kinetics and relatively insensitive to a pH change from 6.5 to 7.0, the non-enzymatic ones were linearly proportional to the GSH concentration and sensitive to pH. The enhanced non-enzymatic conjugation of various electrophiles at high GSH concentrations may in part account for the physiological significance of GSH elevation in preneoplastic and neoplastic cells.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
F. Desmots, M. Rissel, D. Gilot, D. Lagadic-Gossmann, F. Morel, C. Guguen-Guillouzo, A. Guillouzo, and P. Loyer
Pro-inflammatory Cytokines Tumor Necrosis Factor alpha and Interleukin-6 and Survival Factor Epidermal Growth Factor Positively Regulate the Murine GSTA4 Enzyme in Hepatocytes
J. Biol. Chem., May 10, 2002; 277(20): 17892 - 17900.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
R. G. Tirona, E. Tan, G. Meier, and K. S. Pang
Uptake and Glutathione Conjugation of Ethacrynic Acid and Efflux of the Glutathione Adduct by Periportal and Perivenous Rat Hepatocytes
J. Pharmacol. Exp. Ther., December 1, 1999; 291(3): 1210 - 1219.
[Abstract] [Full Text]

Home page
 J. Pharmacol. Exp. Ther.Home page
R. G. Tirona and K. S. Pang
Bimolecular Glutathione Conjugation Kinetics of Ethacrynic Acid in Rat Liver: In Vitro and Perfusion Studies
J. Pharmacol. Exp. Ther., September 1, 1999; 290(3): 1230 - 1241.
[Abstract] [Full Text]

Home page
 Mol. Pharmacol.Home page
D. W. Loe, R. K. Stewart, T. E. Massey, R. G. Deeley, and S. P. C. Cole
ATP-Dependent Transport of Aflatoxin B1 and Its Glutathione Conjugates by the Product of the Multidrug Resistance Protein (MRP) Gene
Mol. Pharmacol., June 1, 1997; 51(6): 1034 - 1041.
[Abstract] [Full Text]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.