In a thiolase-mediated reaction, 2 molecules of acetyl-CoA condense to form acetoacetyl-CoA
, and subsequently 3-hydroxy, 3methylglutaryl-CoA (3-HMG-CoA).
3-Hydroxy-3-methylglutaryl-Coenzyme A synthase(HMGS) is the second enzyme in MVA pathway of isoprenoid biosynthesis, and catalyzes the condensation of acetyl-CoA with acetoacetyl-CoA to yield HMG-CoA.
Biological significance of plant HMGS in the MVA pathway: As an important condensing enzyme in the MVA pathway, HMGS can catalyze condensation of acetyl-CoA and acetoacetyl-CoA to generate HMG-CoA, which is further converted into generate MVA by HMGR.
The subsequent nucleophilic attack on acetoacetyl-CoA (its second substrate) leads to the formation of HMG-CoA (Theisen et al.
Novel acetoacetyl-CoA synthesizing enzyme found in the Streptomyces MVA pathway gene clusters
35) The MVA pathway begins with the synthesis of acetoacetyl-CoA, which was first reported to be biosynthesized via a thioester-dependent Claisen condensation reaction between two molecules of acetyl-CoA, and is catalyzed by acetoacetyl-CoA thiolase (EC 2.
at 340 nm using 50 [micro]M acetoacetyl-CoA
Acetyl-Coenzyme A acetyltransferase 2 (ACAT) transforms acetyl-CoA into acetoacetyl-CoA and can increases the rate of ketogenesis.
Purification, kinetic mechanism and regulation of different forms of mitochondrial acetoacetyl-CoA thiolases from ox liver.
The second genetic disorder included in this study is an organic acid disorder called Mitochondrial acetoacetyl-CoA
thiolase (T2), commonly known as Beta-ketothiolase deficiency.
Activities of 3-hydroxybutyrate dehydrogenase, 3-oxoacid CoA-transferase and acetoacetyl-CoA
thiolase in relation to ketone-body utilisation in muscles from vertebrates and invertebrates.
Increased lipolysis results in the overproduction of acetoacetyl-CoA
, which then acts as the substrate for hepatic formation of ketone bodies.