Biomaterial Database

Properties and subcellular distribution of acyl-CoA: cholesterol acyltransferase (ACAT) in guinea-pig liver. 1978

B Beck, and C A Drevon

The optimal in vivo conditions for measuring liver acyl-CoA:cholesterol acyltransferase, EC.2.2.1.26 (ACAT) activity in cytoplasmic extract from guinea-pigs have been examined. ACAT in liver from ordinarily fed guinea-pigs is very low. The effect of different compounds on ACAT activity was evaluated. Sodium fluoride, oligomycin, divalent cations, oleyl-CoA, and bile acids were all shown to inhibit ACAT activity markedly. Albumin stimulated the cholesterol esterification independently of the presence of fatty acids. Subcellular distribution of liver ACAT in relation to different marker enzymes shows that the bulk of ACAT activity is present in the microsomal fraction. By comparing the esterification of exogenous and endogenous cholesterol, the results indicate that these two substrates are not esterified to the same extent. Both the 'enzyme" level and substrate quality are of importance for the high ACAT activity found in rat-liver homogenates compared to guinea-pig.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D009840	Oligomycins	A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins are RUTAMYCIN, peliomycin, and botrycidin (formerly venturicidin X).	Oligomycin
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D002412	Cations	Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.	Cation
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D002785	Sterol O-Acyltransferase	An enzyme that catalyzes the formation of cholesterol esters by the direct transfer of the fatty acid group from a fatty acyl CoA derivative. This enzyme has been found in the adrenal gland, gonads, liver, intestinal mucosa, and aorta of many mammalian species. EC 2.3.1.26.	Acyl-CoA-Cholesterol Acyltransferase,Cholesterol Acyltransferase,Cholesterol Esterifying Enzyme,Acyl CoA Cholesterol Acyltransferase,Acyltransferase, Acyl-CoA-Cholesterol,Acyltransferase, Cholesterol,Enzyme, Cholesterol Esterifying,Esterifying Enzyme, Cholesterol,O-Acyltransferase, Sterol,Sterol O Acyltransferase
D003065	Coenzyme A		CoA,CoASH
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms