Acyl coenzyme A cholesterol acyltransferase

L. L. Gallo, S. B. Clark, S. Myers, G. V. Vahouny, Cholesterol Absorption in Rat Intestine Role of Cholesterol Esterase and Acyl Coenzyme A Cholesterol Acyltransferase , J. Lipid Res. 1984, 25, 604-612. 

T. F. Woolf, A. Black, Y. Y. Shum, W. Mcnally, H. Lee, T. Chang, BioDisposion Studies with the Acyl-Coenzyme-A-Cholesterol Acyltransferase Inhibitor 2,2-Dimethyl-V-(2,4,6-Trimethoxyphenyfidodecanamide, CI-976 , Drug Metab. Dispos. 1993, 21, 1112-1118. 

Puglielli, L., Konopka, G., Pack-Chung, E., Ingano, L.A., Berezovska, O., Hyman, B.T., Chang, T.Y., Tanzi, R.E., and Kovacs, D.M., Acyl-coenzyme A cholesterol acyltransferase modulates the generation of the amyloid beta-peptide, Nat. Cell Biol., 3, 905, 2001. 

P Oelkers, A Behari, D Cromley, JT Billheimer, SL Sturley. Characterization of two human genes encoding acyl coenzyme A cholesterol acyltransferase-related enzymes. J Biol Chem 273 26765-26771, 1998. 

Fig. 4. Potential sources of the immediate precursor pool of unesterified cholesterol available for mitochondrial steroidogenesis. ACAT, microsomal acyl coenzyme A cholesterol acyltransferase SEH, sterol ester hydrolase. From Ref. 14.

Rumsey, S. C., Galeano, N., Lipschitz, B., and Deckelbaum, R. J. (1995). Oleate and other long-chain fatty acids stimulate low-density-lipoprotein receptor activity by enhancing acyl coenzyme A cholesterol acyltransferase activity and altering intracellular regulatory cholesterol pools in cultured cells. /. Biol. Chem. 270,10008-100016. 

The PEGylation reactions with 38 are usually performed using an excess of the reagent in a darkened flask, in order to Emit the formation of iodine, which can react with other amino acids. mPEG-iodoacetamide is a commercially available reagent that can be prepared by the reaction of mPEG-amine 42 with iodoacetic anhydride in diox-ane [178]. Examples of the use of 38 include the PEGylation of acyl-coenzyme A and cholesterol acyltransferase [198]. 

Gallo, L. L., Wadsworth, J. A., and Vahouny, G. V. (1987) Normal cholesterol absorption in rats deficient in intestinal acyl coenzyme Axholesterol acyltransferase activity. J. Lipid Res. 28, 381-387. 

The major enzymes involved in lipoprotein regulation are (Ij acyl-CoAxholesterol acyl-transferase (ACAT), which esterifies some cholesterol in the core of chylomicrons (2) lec-ithin cholesterol acyltransferase (LCAT), which esterifies cholesterol and helps transfer it to LDL (3) lipoprotein lipase (LPL), which hydrolyzes triglycerides to free fatty acids (FFA) and glycerol and (4) 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which is essential in the synthesis of cholesterol and other steroids in the liver. 

Several systems for formation and hydrolysis of cholesteryl esters in rat liver are known. Microsomes contain an acyl-CoA cholesterol acyltransferase, which requires coenzyme A and ATP for fatty add activation, and operates at neutral pH. Enzymic transfer of fatty adds from lecithin to cholesterol occurs in the soluble fraction of rat liver. A third enzyme, cholesterol esterase, occurs in rat liver and its main function is probably hydrolytic. Although human liver apparently does not have acyl-CoA cholesterol acyltransferase activity, it does have a reversible cholesterol esterase (E.C.3.1.1.13) with optimal... 

---