MolPharm xPharm- The Comprehensive Pharmacology Reference

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
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 Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by REYES, P.
Right arrow Articles by HEIDELBERGER, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by REYES, P.
Right arrow Articles by HEIDELBERGER, C.

Molecular Pharmacology, Vol 1, 14-30, Copyright © 1965 by the American Society for Pharmacology and Experimental Therapeutics

Fluorinated Pyrimidines XXVI. Mammalian Thymidylate Synthetase: Its Mechanism of Action and Inhibition by Fluorinated Nucleotides

PHILIP REYES 1 and CHARLES HEIDELBERGER 1

1 McArdle Laboratory, The Medical School, University of Wisconsin, Madison, Wisconsin

Thymidylate synthetase from Ehrlich ascites carcinomna cells has been assayed by a spectrophotometric method, and several new properties of this enzyme have been discovered. Thymidylate produces a weak noncompetitive product inhibition and mercaptoethanol stimulates the enzyme activity, whereas formaldehyde must be present within a specific concentration range if maximal enzyme activity is to occur. In addition, the results of initial velocity and product-inhibition kinetic studies as well as those of experiments designed to study the kinetics of the inhibition produced by 5-fluoro-2'-deoxyuridine 5'-monophosphate and 5-trifluoromethyl-2'-deoxyuridine 5'-monophosphate made it possible to elucidate the mechanism of action of thymidylate synthetase. The mechanism is ordered and sequential, such that 5,10-methylenetetrahydrofolate interacts with the enzyme before deoxyuridylate, and thymidylate leaves before dihydrofolate. Furthermore, a mechanism without central complexes has been eliminated. 5-Trifluoromethyl-2'-deoxyuridine 5'-monophosphate, unlike 5-fluoro-2'-deoxyuridine 5'-monophosphate, exhibits the ability to combine slowly with the enzyme in an irreversible fashion.

Note:
ACKNOWLEDGMENT The authors would like to thank Professor W. W. Cleland for several valuable and helpful discussions during the course of this investigation. This work was supported in part by grants CRTY-5002 and CA-07175 from the National Cancer Institute, United States Public Health Service, Bethesda, Maryland.

Submitted on February 13, 1965




This article has been cited by other articles:


Home page
 Antimicrob. Agents Chemother.Home page
L. Jiang, P.-C. Lee, J. White, and P. K. Rathod
Potent and Selective Activity of a Combination of Thymidine and 1843U89, a Folate-Based Thymidylate Synthase Inhibitor, against Plasmodium falciparum
Antimicrob. Agents Chemother., April 1, 2000; 44(4): 1047 - 1050.
[Abstract] [Full Text]

Home page
 J. Histochem. Cytochem.Home page
A. S. Haqqani, R. T. Cowling, J. A. Maroun, and H. C. Birnboim
Characterization of a Polyclonal Antibody to Human Thymidylate Synthase Suitable for the Study of Colorectal Cancer Specimens
J. Histochem. Cytochem., December 1, 1999; 47(12): 1563 - 1574.
[Abstract] [Full Text]

Home page
 ScienceHome page
B. Shoichet, R. Stroud, D. Santi, I. Kuntz, and K. Perry
Structure-based discovery of inhibitors of thymidylate synthase
Science, March 5, 1993; 259(5100): 1445 - 1450.
[Abstract] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 1965 by the American Society for Pharmacology and Experimental Therapeutics