Acetoacetyl-CoA also behaves as a product of acetoacetyl-CoA synthetase (AACS) within the cytosol, using acetoacetate as the substrate, the reaction provides acetyl groups for lipogenesis. [8] Understanding acetoacetyl-CoA is important in cholesterol development and lipogenesis and Acetoacetyl-CoA synthetase playing a role in its development ...

Ketone bodies are the name given to two molecules, acetoacetate (a ketone) and D-β-hydroxybutyrate (its reduction product) that derive from the condensation of acetate in the form of acetyl-CoA. Their structures are shown in Figure \(\PageIndex{1}\).

2023年2月6日 · Two acetyl-CoA molecules are converted into acetoacetyl-CoA via the enzyme thiolase; this is also known as acetyl coenzyme A acetyltransferase (ACAT). Afterward, acetoacetyl-CoA is converted to HMG-CoA via the enzyme HMG-CoA synthase. HMG-CoA lyase then converts HMG-CoA to acetoacetate.

The reaction catalyzed by acetoacetyl-CoA synthase. Stage 1: condensation of one molecule of acetyl-CoA with the enzyme, represented as H—SE, releases CoA-SH and forms an enzyme-bound thioester. Stage 2: a basic group on the enzyme (E—B:) facilitates loss of the α-proton of a second molecule of acetyl-CoA (bold), forming a C-2 anion.

Acetyl-CoA is catalyzed by acetyl-CoA acetyltransferase (AACT) to form acetoacetyl-CoA (Miziorko, 2011), and two molecules of acetoacetyl-CoA are combined by 3-hydroxy-3-methylglutaryl CoA synthase (HMGS) to form HMG-CoA, which is converted into MVA acid in the presence of HMG-CoA reductase (HMGR). Then the product is sequentially ...

2008年10月18日 · Acetate is readily taken up by cells and is activated to acetyl-CoA in both the cytosol and mitochondria by acetyl-CoA synthetase. Acetyl-CoA is a common metabolic intermediate for synthesis of cholesterol and fatty acids, which are then incorporated into membrane tissue (1).

The first acetyl group of acetyl-CoA is transferred into acetoacetyl-CoA, which is produced during the last cycle of β-oxidation of fatty acids to form 3-hydroxy-3-methylglucenyl-CoA. Then, acetyl-CoA is regenerated from 3-hydroxy-3-methyl-3-methylglucosyl CoA and results in the production of ATA (Fig. 2) (Ruderman et al., 1974).

Synthesis from acetyl CoA: Acetoacetate. Acetoacetate can be reduced. Subsequently acetoacetate can be reduced to beta-hydroxybutyrate by beta-hydroxybutyrate dehydrogenase in a NADH-requiring reaction.

E. coli grows on acetoacetate by first converting it to acetoacetyl-CoA using the acetyl-CoA:acetotacetate CoA transferase enzyme (AtoDA, EC 2.8.3.8). In the second step of the pathway, the 3-ketoacyl-CoA thiolase (AtoB, EC 2.3.1.16) enzyme converts acetoacetyl-CoA and CoA to two molecules of acetyl-CoA, which enter central metabolism ( Fig. 4A ...

TAX-562 is able to utilize acetoacetate as a total source of carbon and energy via the two-step pathway shown here. As end-product, the pathway has a net yield of one molecule of acetyl-CoA which feeds into central metabolism via the TCA cycle. Use of acetoacetate as a substrate increases the levels of these two enzymes 200- to 300-fold.