Chlorothricin is a spirotetronic acid antibiotic inhibitor of pyruvate carboxylase.
The tetronic acid, chlorothricin, is an unusual macrocyclic antibiotic from a Streptomyces sp., related to kijanimicin, saccharocarcins, tetrocarcins and versipelostatin. Chlorothricin inhibits cholesterol biosynthesis from mevalonate, and inhibits pyruvate carboxylases purified from rat liver, chicken liver and Azotobacter vinelandii.
chlorothricin is a macrolide-type antibiotic.macrolides, a class of natural products belonging to the polyketide class of natural products, consist of a large macrocyclic lactone ring. the lactone rings are oftem 14-, 15-, or 16-membered. some macrolides have been reported to have antibiotic or antifungal activity and are widely used as pharmaceutical drugs.
in a previous study, chlorothricin was found to inhibit the reaction catalyzed by pyruvate carboxylase from bacillus stearothermophilus. moreover, with steady-state kinetic measurements, inhibition of the overall reaction was found to be competitive with the allosteric activator of this enzyme, coasac, and non-competitive with respect to both substrates of mgatp and pyruvate. these findings strongly indicated that the site 1conformation of pyruvate carboxylase responsible for the regulation of the overall enzyme activity could be influenced by chlorothricin and coasac in an antagonistic manner [1].
173, 500, 260, and 120 μm for pyruvate carboxylases from bacillus, azotobacter, rat, and chicken, respectively.
[1] schindler pw, zhner h. mode of action of the macrolide-type antibiotic, chlorothricin. kinetic study of the inhibition of pyruvate carboxylase from bacillus stearothermophilus. eur j biochem. 1973 nov 15;39(2):591-600.
