Biotin has a profound effect on the metabolism of rhizobia. It is reported here that the activities of the biotin-dependent enzymes acetyl-coenzyme A carboxylase (ACC; EC 6.4.1.2) and propionyl-coenzyme A carboxylase (PCC; EC 6.4.1.3) are present in all species of the five genera comprising the Rhizobiaceae which were examined. Evidence is presented that the ACC and PCC activities detectable in...

medium containing [” Plphosphate, the distribution of 32P-labelled acetyl-CoA carboxylase in the fractions can be investigated and it has been found that a greater proportion of the phosphorylated enzyme is present in the polymeric form after exposure of the intact tissue to insulin. Present studies are concerned with investigating whether this polymeric active form is phosphorylated to a great...

The possibility of a regulatory role of long-chain acyl-CoAs was studied in a system synthesizing palmitoyl-CoA and stearoyl-CoA in vitro. This system contained acetyl-CoA carboxylase (yeast), fatty acid synthetase (yeast) and lipid membranes as acceptors for the long-chain acyl-CoA compounds. In this system acetyl-CoA carboxylase is controlled by long-chain acyl-CoAs, whereas this is not true ...

The short-term regulation of rat liver acetyl-CoA carboxylase by glucagon has been studied in hepatocytes from rats that had been fasted and refed a fat-free diet. Glucagon inhibition of the activity of this enzyme can be accounted for by a direct correlation between phosphorylation, polymer-protomer ratio, and activity. Glucagon rapidly inactivates acetyl-CoA carboxylase with an accompanying 4...

We have previously shown that bolus intravenous administration of tumor necrosis factor (TNF) to normal rats results in a rapid (within 90 min) stimulation of hepatic fatty acid synthesis, which is sustained for 17 hr. We now demonstrate that TNF stimulates fatty acid synthesis by several mechanisms. Fatty acid synthetase and acetyl-CoA carboxylase (measured after maximal stimulation by citrate...

Short-term exposure of isolated rat hepatocytes to short- and medium-chain fatty acids led to an activation of acetyl-CoA carboxylase as measured in digitonin-permeabilized hepatocytes. Up to a certain concentration, typical for each of the fatty acids used, fatty acid-dependent activation of acetyl-CoA carboxylase coincided with an increase in the rate of fatty acid synthesis in intact hepatoc...

Five classes of herbicides (carbamothioates, chloroacetamides, substituted pyridazinones, cyclohexanediones, and aryloxyphenoxypropionic acids) have been reported to inhibit lipid biosynthesis in higher plants. Carbamothioates impair the synthesis of surface lipids (waxes, cutin, suberin). These effects have been attributed to the ability of this herbicide class to inhibit one or more acyl-CoA ...