Effect of the Thiol-Oxidizing Agent, Diamide, on Cerebral Cortical Na(+) -K(+) ATPase
Abstract
This study documents the action of the thiol-oxidizing agent, diamide, on the Na+-K+ ATPase, and compares it with other sulfhydryl inhibitors. Diamide inhibits the activity of in vitro cerebral cortical and whole brain synaptosomal Na+K+ ATPase. Complete inhibition occurs at 0.1 M diamide, with a progressive increase in enzyme activity occurring sigmoidally to 100% activity at 1 micrometers diamide. The diamide-induced inhibition of the Na+-K+ ATPase activity is not reversed by washing with diamide-free media. However, partial reversal of inhibition is possible when the diamide-treated enzyme is incubated with the thiol-reducing agents dithiothreitol or cysteine. Partial protection against diamide-induced sulfhydryl oxidation was obtained in the presence of Na+ and ATP, whereas, addition of Mg2+ and K+ decreases the level of protection. Therefore, the reactivity of diamide on the sulfhydryl groups of the catalytic subunit is dependent upon the conformational state of the enzyme.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1988
- Accession Number
- ADA205311
Entities
People
- Carol A. Colton
- Joel S. Colton
- Sara C. Gilman
Organizations
- Naval Medical Research Center