We have briefly proposed (1) the general theory that “acetate-derived” aromatic metabolites arise ana.logously to fatty acids, by repeated condensation of malonyl coenzyme A units with an acyl coenzyme A “starter,” citing in support our own work on the 6-methylsalicylic acid of Penicillium urticae and the prior report of Bentley and Keil (2) on penicillic acid. A number of subsequent publicatio...

Fatty acid-biosynthetic activity in rat liver cytosol fractions is much greater when the bivalent cation in the assay system is Mn(2+) than when it is Mg(2+). This difference between bivalent cations can be abolished if the cytosol fractions are preincubated with isocitrate and the bivalent cation for 30min before assay of fatty acid-biosynthetic activity. In a search for the biochemical basis ...

The study was designed to evaluate whether changes in malonyl-CoA and the enzymes that govern its concentration occur in human muscle as a result of physical training. Healthy, middle-aged subjects were studied before and after a 12-wk training program that significantly increased VO2 max by 13% and decreased intra-abdominal fat by 17%. Significant decreases (25-30%) in the concentration of mal...

Acyl carrier protein from Euglena gracilis strain Z was purified to electrophoretic homogeneity. The molecular weight was estimated to be 10,400. An amino acid composition was done and related to those of similar proteins from other sources. The activity in the CO*-malonyl coenzyme A exchange reaction with fatty acid synthetase enzymes (type II) from Eugkna was less than that of Escherichiu col...

There has been considerable interest in the observation that the overt form of carnitine palmitoyltransferase (CPT1) in liver mitochondria is potently inhibited by malonyl CoA [I ,2]. It has been suggested [2] that this is a competitive type of inhibition against long chain acyl CoA substrates. However, this is based upon measurements of ketogenesis [3-51 or indirect calculations of CPT, activi...

Acute increases in the concentration of malonyl-CoA play a pivotal role in mediating the decrease in fatty acid oxidation that occurs in many tissues during refeeding after a fast. In this study, we assess whether such increases in malonyl-CoA in liver could be mediated by malonyl-CoA decarboxylase (MCD), as well as acetyl-CoA carboxylase (ACC). In addition, we examine how changes in the activi...

Acetyl coenzyme A (acetyl-CoA) carboxylase (ACC) catalyzes carboxylation of acetyl-CoA to form malonyl-CoA. In mammals, two isozymes exist with distinct physiological roles: cytosolic ACC1 participates in de novo lipogenesis (DNL), and mitochondrial ACC2 is involved in negative regulation of mitochondrial beta-oxidation. Since systemic ACC1 null mice were embryonic lethal, to clarify the physio...

The capacity of liver to synthesize long-chain fatty acids is greatly enhanced during early linoleate deficiency in mice. The enzymes catalyzing the synthesis of fatty acids from acetate or malonyl CoA were measured directly in soluble fractions isolated from fiver. The period of dietary restriction of linoleate is also accompanied by a rapid fall in the relative linoleate content of the liver;...

Malonyl-CoA decarboxylase (MCD), which catalyzes the conversion of malonyl-CoA to acetyl-CoA, is an evolutionarily distinct and highly conserved enzyme. MCD does not share sequence homology with other known decarboxylases, while the enzymes from different species exhibit at least >30% sequence identity to each other. In order to provide a canonical structure of the enzyme for detailed study of ...