The inhibition by saccharin and cyclamate of phosphotransferase and phosphohydrolase activities of glucose-6-phosphatase

Authors

David G. Lygre, Central Washington University

Department or Administrative Unit

Chemistry

Document Type

Article

Author Copyright

Copyright © 1974 Published by Elsevier B.V.

Publication Date

3-1974

Journal

Biochimica et Biophysica Acta (BBA) - Enzymology

Abstract

Saccharin and cyclamate were found to inhibit the glucose-6-phosphate phosphohydrolase and PP_i-glucose phosphotransferase activities of beef liver microsomal glucose-6-phosphatase (D-glucose-6-phosphate phosphohydrolase, EC 3.1.3.9). The extent of inhibition decreased with increasing pH in the range pH 4–8. At pH 5.6 inhibition by both compounds was competitive with respect to phosphate substrates and non-competitive with respect to glucose K_i values for saccharin and cyclamate were, respectively, 6.5 and 26 mM for the phosphohydrolase reaction, and were 16 and 68 mM with respect to PP_i and 110 and 190 mM with respect to glucose for the phosphotransferase reaction. Of a variety of structural analogs of saccharin and cyclamate, saccharin was the most effective inhibitor tested.

Comments

This article was originally published in Biochimica et Biophysica Acta (BBA) - Enzymology. The full-text article from the publisher can be found here.

Due to copyright restrictions, this article is not available for free download from ScholarWorks @ CWU.

Recommended Citation

Lygre, D. G. (1974). The inhibition by saccharin and cyclamate of phosphotransferase and phosphohydrolase activities of glucose-6-phosphatase. Biochimica et Biophysica Acta (BBA) - Enzymology, 341(1), 291–297. https://doi.org/10.1016/0005-2744(74)90090-4