1. Pyruvate carboxylase from baker's yeast is inhibited by ADP, AMP and adenosine at pH8.0 in the presence of magnesium chloride concentrations equal to or higher than the ATP concentration. The adenine moiety is essential for the inhibitory effect. 2. In the absence of acetyl-CoA (an allosteric activator) ADP, AMP and adenosine are competitive inhibitors with respect to ATP. In the presence of...

a clinical presentation of a metabolic disorder, often first seen in infants who present with poor feeding, vomiting, tachypnea, acidosis, hyperammonemia, ketosis, ketonuria, irritability, and convulsions or hypotonia and lethargy, findings that are otherwise suggestive of neonatal sepsis diseases with oa isovaleric and propionic acidemias, maple syrup urine disease, medium chain acyl dehydroge...

Liver acetyl-CoA carboxylase, a biotin-enzyme which catalyzes the ATP-dependent carboxylation of acetyl-CoA (acceptor) to form malonyl-CoA (carboxylated acceptor), decarboxylates malonyl-CoA by a biotin-dependent, as well as a biotin-independent mechanism. Neither ADP, Pi, nor divalent metal ion are required for either of these abortive decarboxylations. The biotin-dependent reaction is blocked...

Biotin-containing proteins are found in all forms of life, and they catalyze carboxylation, decarboxylation, or transcarboxylation reactions that are central to metabolism. In plants, five biotin-containing proteins have been characterized. Of these, four are catalysts, namely the two structurally distinct acetyl-CoA carboxylases (heteromeric and homomeric), 3-methylcrotonyl-CoA carboxylase and...

Acetyl-CoA carboxylase catalyzes the carboxylation of acetyl-CoA to malonyl-CoA. This reaction constitutes the first committed step of fatty acid synthesis in most organisms, while its product also serves as a universal precursor for various other high-value compounds. The important regulatory and rate-limiting role of acetyl-CoA carboxylase makes this enzyme a powerful tool in a variety of bio...

Geranyl-CoA carboxylase (GCC) is essential for the growth of Pseudomonas organisms with geranic acid as the sole carbon source. GCC has the same domain organization and shares strong sequence conservation with the related biotin-dependent carboxylases 3-methylcrotonyl-CoA carboxylase (MCC) and propionyl-CoA carboxylase (PCC). Here we report the crystal structure of the 750-kDa α6β6 holoenzyme o...

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...

Previous studies with propionyl coenzyme A carboxylase and with phosphoenolpyruvate carboxylase using ‘*O-labeled bicarbonate have indicated that bicarbonate is the reactive species in these fixations of “C02.” We have investigated the species of CO:! in reactions catalyzed by pyruvate carboxylase, P-enolpyruvate carboxykinase, and P-enolpyruvate carboxytransphosphorylase. Since propionyl-CoA c...

Acetyl CoA carboxylase (ACC) 2, which catalyzes the carboxylation of acetyl-CoA to form malonyl-CoA, has been identified as a potential target for type 2 diabetes and obesity. Small-molecule inhibitors of ACC2 would be expected to reduce de novo lipid synthesis and increase lipid oxidation. Treatment of ob/ob mice with compound A-908292 (S) ({(S)-3-[2-(4-isopropoxy-phenoxy)-thiazol-5-yl]-1-meth...