PMID:42643
| Citation |
Kameshita, I, Tokushige, M, Izui, K and Katsuki, H (1979) Phosphoenolpyruvate carboxylase of Escherichia coli. Affinity labeling with bromopyruvate. J. Biochem. 86:1251-7 |
|---|---|
| Abstract |
Phosphoenolpyruvate carboxylase [EC 4.1.1.31] from Escherichia coli W was alkylated by incubation with bromopyruvate, substrate analog, leading to irreversible inactivation. The reaction followed pseudo-first-order kinetics. Mg2+, an essential cofactor for catalysis, enhanced the inactivation, and the enhancing effect increased as the pH increased. The inactivation rate showed a tendency to saturate with increasing concentrations of bromopyruvate, indicating that an enzyme-bromopyruvate complex was formed prior to the alkylation. DL-Phospholactate, a potent competitive inhibitor with respect to phosphoenolpyruvate, protected the enzyme from inactivation in a competitive manner. Examination of the acid hydrolysate of the enzyme modified with [14C]bromopyruvate by paper chromatography showed that radioactivity was solely incorporated into carboxyhydroxyethyl cysteine. In addition, determination of sulfhydryl groups of the native and modified enzymes with 5,5'-dithiobis(2-nitrobenzoate) showed that inactivation occurred concomitant with the modification of one cysteinyl residue per subunit. The results indicate that bromopyruvate reacted with the enzyme as an active-site-directed reagent. |
| Links | |
| Keywords |
Affinity Labels/pharmacology; Binding Sites; Carboxy-Lyases/metabolism; Cysteine/analysis; Escherichia coli/enzymology; Hydrogen-Ion Concentration; Kinetics; Phosphoenolpyruvate Carboxylase/metabolism; Protein Binding; Pyruvates/pharmacology |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.