Acetyl-CoA acetyltransferase

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Acetyl-CoA acetyltransferase
Acetyl-CoA acetyltransferase
Surface models of the ACAT1 tetramer (from above, from the side) according to PDB  2IBW
Mass / length primary structure approx. 395 amino acids
Secondary to quaternary structure Homotetramer
Cofactor potassium
Identifier
Gene name (s) ACAT1 , ACAT2
Enzyme classification
EC, category 2.3.1.9 ,  Transferase
Response type Transfer of an acetyl group
Substrate 2 acetyl CoA
Products CoA + acetoacetyl-CoA

Acetyl-CoA-acetyltransferase (ACAT) (also: 3-ketothiolase or thiolase II) are called enzymes that catalyze the acetylation of acetyl-coenzyme A and the reverse reaction . These reactions are necessary to build up and break down ketone bodies , but also in the biosynthesis of steroids and in the breakdown of some amino acids. ACAT occurs in all living things and in eukaryotes in two copies, one in the cytosol (ACAT2) and one in the mitochondria (ACAT1). Defects in ACAT1 - gene are probably associated with a rare metabolic disease.

In a Chinese study, ACAT1 variants were associated with altered LDL and nHDL cholesterol levels . A similar observation was made earlier in a Japanese study. ACAT in macrophages , however, appears to play an important role in controlling lipids in foam cells .

Catalyzed equilibrium

2 Acetyl-CoA⇔ CoA-SH +Acetoacetyl-CoA

Two molecules of acetyl-CoA are converted into coenzyme A and acetoacetyl-CoA and vice versa.

Individual evidence

  1. ↑ UniProt P24752 , UniProt Q9BWD1
  2. ↑ Li Q, Bai H, Fan P: [Analysis of acyl-coenzyme A: cholesterol acyltransferase 1 polymorphism in patients with endogenous hypertriglyceridemia in Chinese population] . In: Zhonghua Yi Xue Yi Chuan Xue Za Zhi . 25, No. 2, April 2008, pp. 206-10. PMID 18393248 .
  3. ↑ Ohta T, Takata K, Katsuren K, Fukuyama S: The influence of the acyl-CoA: cholesterol acyltransferase-1 gene (-77G → A) polymorphisms on plasma lipid and apolipoprotein levels in normolipidemic and hyperlipidemic subjects . In: Biochim. Biophys. Acta . 1682, No. 1-3, June 2004, pp. 56-62. doi : 10.1016 / j.bbalip.2004.01.008 . PMID 15158756 .
  4. ↑ Su YR, Dove DE, Major AS, et al : Reduced ABCA1-mediated cholesterol efflux and accelerated atherosclerosis in apolipoprotein E-deficient mice lacking macrophage-derived ACAT1 . In: Circulation . 111, No. 18, May 2005, pp. 2373-81. doi : 10.1161 / 01.CIR.0000164236.19860.13 . PMID 15851589 .
  5. ↑ Fazio S, Major AS, Swift LL, et al : Increased atherosclerosis in LDL receptor-null mice lacking ACAT1 in macrophages . In: J. Clin. Invest. . 107, No. 2, January 2001, pp. 163-71. doi : 10.1172 / JCI10310 . PMID 11160132 . PMC 198874 (free full text).

Web links

Wikibooks: Biochemie_und_Pathobiochemie: ketone body biosynthesis  - learning and teaching materials