Pyruvate carboxylase (PC) was purified to homogeneity from an overexpressing strain of the purple photosynthetic bacterium Rhodobacter capsulatus using a rapid dye-ligand affinity chromatography procedure, in which dye-bound enzyme was specifically eluted with a low concentration of acetyl-CoA, an allosteric activator of the enzyme. The enzyme purified by this method was obtained in 75% yield w...

In isolated hepatocytes prepared from unfed neonatal chicks, stimulation of fatty acid synthesis by fructose or dihydroxyacetone required acetate or octanoate in the medium, suggesting that the stimulatory effect of these compounds required the enhanced production of intramitochondrial acetyl coenzyme A. Stimulation of fatty acid synthesis by lactate or pyruvate did not require a supplementary ...

Fasted (48 h) rats were killed at 0, 2, 4, 6, 8, 12, 16, 20 and 24 h after they were refed on a high-carbohydrate diet. An increase in the maximal activity and quantity of cystolic acetyl-CoA carboxylase was found in liver of refed rats after a lag time of about 8 h. The increased quantity of cytosolic enzyme was attributable primarily to mobilization of mitochondrial storage forms and not to s...

Acetyl-CoA Carboxylase catalyzes the first committed step in fatty acid synthesis. Escherichia coli acetyl-CoA carboxylase is composed of biotin carboxylase, carboxyltransferase and biotin carboxyl carrier protein functions. The accA and accD genes that code for the alpha- and beta-subunits, respectively, are not in an operon, yet yield an alpha(2)beta(2) carboxyltransferase. Here, we report th...

Acetyl coenzyme A (CoA) carboxylase activity of whole tissue homogenates and chloroplast preparations was analyzed as the acetyl-CoA-dependent incorporation of [(14)C]bicarbonate into an acid-stable product. The absolute requirement for ATP and MgCl(2), the complete inhibition with avidin, and end-product analysis were consistent with the presence of acetyl-CoA carboxylase activity. Little diff...

Studies presented here, with the criterion of the degree of binding of the biotin derivatives obtained from acetyl coenzyme A carboxylase to avidin, show that these compounds have an intact ureido ring, eliminating the diamine derivative as an intermediate in the carboxylation. With the use of carboxyl-14C-biotin acetyland propionyl-CoA carboxylases, it has been possible to show both in vivo an...