Carnitine
A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism.
Acyltransferases
Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.
Carnitine O-Palmitoyltransferase
An enzyme that catalyzes reversibly the conversion of palmitoyl-CoA to palmitoylcarnitine in the inner mitochondrial membrane. EC 2.3.1.21.
Carnitine O-Acetyltransferase
An enzyme that catalyzes the formation of O-acetylcarnitine from acetyl-CoA plus carnitine. EC 2.3.1.7.
Carnitine Acyltransferases
Acyltransferases in the inner mitochondrial membrane that catalyze the reversible transfer of acyl groups from acyl-CoA to L-carnitine and thereby mediate the transport of activated fatty acids through that membrane. EC 2.3.1.
Glycerol-3-Phosphate O-Acyltransferase
An enzyme that transfers acyl groups from acyl-CoA to glycerol-3-phosphate to form monoglyceride phosphates. It acts only with CoA derivatives of fatty acids of chain length above C-10. Also forms diglyceride phosphates. EC 2.3.1.15.
Phosphatidylcholine-Sterol O-Acyltransferase
An enzyme secreted from the liver into the plasma of many mammalian species. It catalyzes the esterification of the hydroxyl group of lipoprotein cholesterol by the transfer of a fatty acid from the C-2 position of lecithin. In familial lecithin:cholesterol acyltransferase deficiency disease, the absence of the enzyme results in an excess of unesterified cholesterol in plasma. EC 2.3.1.43.
Diacylglycerol O-Acyltransferase
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.
Lecithin Acyltransferase Deficiency
An autosomal recessively inherited disorder caused by mutation of LECITHIN CHOLESTEROL ACYLTRANSFERASE that facilitates the esterification of lipoprotein cholesterol and subsequent removal from peripheral tissues to the liver. This defect results in low HDL-cholesterol level in blood and accumulation of free cholesterol in tissue leading to a triad of CORNEAL OPACITY, hemolytic anemia (ANEMIA, HEMOLYTIC), and PROTEINURIA.
1-Acylglycerophosphocholine O-Acyltransferase
An enzyme localized predominantly within the plasma membrane of lymphocytes. It catalyzes the transfer of long-chain fatty acids, preferentially unsaturated fatty acids, to lysophosphatides with the formation of 1,2-diacylglycero-3-phosphocholine and CoA. EC 2.3.1.23.
Acyl Coenzyme A
S-Acyl coenzyme A. Fatty acid coenzyme A derivatives that are involved in the biosynthesis and oxidation of fatty acids as well as in ceramide formation.
Acetylcarnitine
An acetic acid ester of CARNITINE that facilitates movement of ACETYL COA into the matrices of mammalian MITOCHONDRIA during the oxidation of FATTY ACIDS.
Palmitoyl Coenzyme A
Malonyl Coenzyme A
A coenzyme A derivative which plays a key role in the fatty acid synthesis in the cytoplasmic and microsomal systems.
gamma-Butyrobetaine Dioxygenase
1-Acylglycerol-3-Phosphate O-Acyltransferase
Organic Cation Transport Proteins
Esterification
The process of converting an acid into an alkyl or aryl derivative. Most frequently the process consists of the reaction of an acid with an alcohol in the presence of a trace of mineral acid as catalyst or the reaction of an acyl chloride with an alcohol. Esterification can also be accomplished by enzymatic processes.
Fatty Acids
Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)
Palmitoylcarnitine
A long-chain fatty acid ester of carnitine which facilitates the transfer of long-chain fatty acids from cytoplasm into mitochondria during the oxidation of fatty acids.
Coenzyme A
Cholesterol Esters
Fatty acid esters of cholesterol which constitute about two-thirds of the cholesterol in the plasma. The accumulation of cholesterol esters in the arterial intima is a characteristic feature of atherosclerosis.
Liver
Triglycerides
Mitochondria, Liver
Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)
Cholesterol
Apolipoprotein A-I
The most abundant protein component of HIGH DENSITY LIPOPROTEINS or HDL. This protein serves as an acceptor for CHOLESTEROL released from cells thus promoting efflux of cholesterol to HDL then to the LIVER for excretion from the body (reverse cholesterol transport). It also acts as a cofactor for LECITHIN CHOLESTEROL ACYLTRANSFERASE that forms CHOLESTEROL ESTERS on the HDL particles. Mutations of this gene APOA1 cause HDL deficiency, such as in FAMILIAL ALPHA LIPOPROTEIN DEFICIENCY DISEASE and in some patients with TANGIER DISEASE.
Betaine
A naturally occurring compound that has been of interest for its role in osmoregulation. As a drug, betaine hydrochloride has been used as a source of hydrochloric acid in the treatment of hypochlorhydria. Betaine has also been used in the treatment of liver disorders, for hyperkalemia, for homocystinuria, and for gastrointestinal disturbances. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1341)
Microsomes
Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Retinol O-Fatty-Acyltransferase
An enzyme that catalyzes the acyl group transfer of acyl COENZYME A to RETINOL to generate COENZYME A and a retinyl ester.
Pentanoic Acids
Esters
Substrate Specificity
Phosphatidylcholines
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.
Phospholipids
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
Lipid Metabolism
Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.
Palmitic Acids
A group of 16-carbon fatty acids that contain no double bonds.
Lipoproteins, HDL
A class of lipoproteins of small size (4-13 nm) and dense (greater than 1.063 g/ml) particles. HDL lipoproteins, synthesized in the liver without a lipid core, accumulate cholesterol esters from peripheral tissues and transport them to the liver for re-utilization or elimination from the body (the reverse cholesterol transport). Their major protein component is APOLIPOPROTEIN A-I. HDL also shuttle APOLIPOPROTEINS C and APOLIPOPROTEINS E to and from triglyceride-rich lipoproteins during their catabolism. HDL plasma level has been inversely correlated with the risk of cardiovascular diseases.
Microbodies
Rats, Inbred Strains
Lipid Metabolism, Inborn Errors
Errors in the metabolism of LIPIDS resulting from inborn genetic MUTATIONS that are heritable.
Oleic Acids
A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Epoxy Compounds
Microsomes, Liver
Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.
Lysophosphatidylcholines
Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.
Ketone Bodies
The metabolic substances ACETONE; 3-HYDROXYBUTYRIC ACID; and acetoacetic acid (ACETOACETATES). They are produced in the liver and kidney during FATTY ACIDS oxidation and used as a source of energy by the heart, muscle and brain.
Caprylates
Derivatives of caprylic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a carboxy terminated eight carbon aliphatic structure.
Palmitates
Salts and esters of the 16-carbon saturated monocarboxylic acid--palmitic acid.
Vitamin B Deficiency
A condition due to deficiency in any member of the VITAMIN B COMPLEX. These B vitamins are water-soluble and must be obtained from the diet because they are easily lost in the urine. Unlike the lipid-soluble vitamins, they cannot be stored in the body fat.
Amino Acid Sequence
Oleic Acid
Lipids
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
Dithionitrobenzoic Acid
Waxes
A plastic substance deposited by insects or obtained from plants. Waxes are esters of various fatty acids with higher, usually monohydric alcohols. The wax of pharmacy is principally yellow wax (beeswax), the material of which honeycomb is made. It consists chiefly of cerotic acid and myricin and is used in making ointments, cerates, etc. (Dorland, 27th ed)
Lipoproteins
Lipid-protein complexes involved in the transportation and metabolism of lipids in the body. They are spherical particles consisting of a hydrophobic core of TRIGLYCERIDES and CHOLESTEROL ESTERS surrounded by a layer of hydrophilic free CHOLESTEROL; PHOSPHOLIPIDS; and APOLIPOPROTEINS. Lipoproteins are classified by their varying buoyant density and sizes.
Hypolipoproteinemias
Conditions with abnormally low levels of LIPOPROTEINS in the blood. This may involve any of the lipoprotein subclasses, including ALPHA-LIPOPROTEINS (high-density lipoproteins); BETA-LIPOPROTEINS (low-density lipoproteins); and PREBETA-LIPOPROTEINS (very-low-density lipoproteins).
Lysophospholipase
Corneal Opacity
Oxidation-Reduction
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Palmitic Acid
Clofibrate
Apolipoproteins
Protein components on the surface of LIPOPROTEINS. They form a layer surrounding the hydrophobic lipid core. There are several classes of apolipoproteins with each playing a different role in lipid transport and LIPID METABOLISM. These proteins are synthesized mainly in the LIVER and the INTESTINES.
Monoglycerides
GLYCEROL esterified with a single acyl (FATTY ACIDS) chain.
Apolipoproteins A
Structural proteins of the alpha-lipoproteins (HIGH DENSITY LIPOPROTEINS), including APOLIPOPROTEIN A-I and APOLIPOPROTEIN A-II. They can modulate the activity of LECITHIN CHOLESTEROL ACYLTRANSFERASE. These apolipoproteins are low in atherosclerotic patients. They are either absent or present in extremely low plasma concentration in TANGIER DISEASE.
Diglycerides
Lipoylation
Acetyl Coenzyme A
Acetyl CoA participates in the biosynthesis of fatty acids and sterols, in the oxidation of fatty acids and in the metabolism of many amino acids. It also acts as a biological acetylating agent.
3-Hydroxybutyric Acid
BUTYRIC ACID substituted in the beta or 3 position. It is one of the ketone bodies produced in the liver.
Palmitoyl-CoA Hydrolase
Enzyme catalyzing reversibly the hydrolysis of palmitoyl-CoA or other long-chain acyl coenzyme A compounds to yield CoA and palmitate or other acyl esters. The enzyme is involved in the esterification of fatty acids to form triglycerides. EC 3.1.2.2.
Biological Transport
Acetyltransferases
Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.
Carrier Proteins
Reye Syndrome
Cloning, Molecular
Mutation
Gene Expression Regulation, Enzymologic
Vitamin A
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
Sequence Homology, Amino Acid
Octoxynol
Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.
Lysophospholipids
Derivatives of PHOSPHATIDIC ACIDS that lack one of its fatty acyl chains due to its hydrolytic removal.
Acyl Carrier Protein
Consists of a polypeptide chain and 4'-phosphopantetheine linked to a serine residue by a phosphodiester bond. Acyl groups are bound as thiol esters to the pantothenyl group. Acyl carrier protein is involved in every step of fatty acid synthesis by the cytoplasmic system.
Base Sequence
Chromatography, Thin Layer
Escherichia coli
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
RNA, Messenger
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
DNA, Complementary
Tissue Distribution
Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.
Phosphatidic Acids
Fatty acid derivatives of glycerophosphates. They are composed of glycerol bound in ester linkage with 1 mole of phosphoric acid at the terminal 3-hydroxyl group and with 2 moles of fatty acids at the other two hydroxyl groups.
Fatty Acids, Nonesterified
FATTY ACIDS found in the plasma that are complexed with SERUM ALBUMIN for transport. These fatty acids are not in glycerol ester form.
Carbon Radioisotopes
Polyketide Synthases
Mitochondria
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Membrane Lipids
Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.
Lipoprotein-X
An abnormal lipoprotein present in large amounts in patients with obstructive liver diseases such as INTRAHEPATIC CHOLESTASIS. LP-X derives from the reflux of BILE lipoproteins into the bloodstream. LP-X is a low-density lipoprotein rich in free CHOLESTEROL and PHOSPHOLIPIDS but poor in TRIGLYCERIDES; CHOLESTEROL ESTERS; and protein.
Phosphatidate Phosphatase
Subcellular Fractions
Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)
Sterol Esterase
An enzyme that catalyzes the hydrolysis of CHOLESTEROL ESTERS and some other sterol esters, to liberate cholesterol plus a fatty acid anion.
Seeds
Hydroxymethylglutaryl CoA Reductases
Hyperammonemia
Myocardium
Lipase
An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. It is produced by glands on the tongue and by the pancreas and initiates the digestion of dietary fats. (From Dorland, 27th ed) EC 3.1.1.3.
Isoenzymes
Lipid A
Lipoproteins, LDL
A class of lipoproteins of small size (18-25 nm) and light (1.019-1.063 g/ml) particles with a core composed mainly of CHOLESTEROL ESTERS and smaller amounts of TRIGLYCERIDES. The surface monolayer consists mostly of PHOSPHOLIPIDS, a single copy of APOLIPOPROTEIN B-100, and free cholesterol molecules. The main LDL function is to transport cholesterol and cholesterol esters to extrahepatic tissues.
Penicillium
A mitosporic Trichocomaceae fungal genus that develops fruiting organs resembling a broom. When identified, teleomorphs include EUPENICILLIUM and TALAROMYCES. Several species (but especially PENICILLIUM CHRYSOGENUM) are sources of the antibiotic penicillin.
Apolipoprotein A-II
The second most abundant protein component of HIGH DENSITY LIPOPROTEINS or HDL. It has a high lipid affinity and is known to displace APOLIPOPROTEIN A-I from HDL particles and generates a stable HDL complex. ApoA-II can modulate the activation of LECITHIN CHOLESTEROL ACYLTRANSFERASE in the presence of APOLIPOPROTEIN A-I, thus affecting HDL metabolism.
Clofibric Acid
An antilipemic agent that is the biologically active metabolite of CLOFIBRATE.
Phospholipases
Dietary Fats
Fats present in food, especially in animal products such as meat, meat products, butter, ghee. They are present in lower amounts in nuts, seeds, and avocados.
Mersalyl
A toxic thiol mercury salt formerly used as a diuretic. It inhibits various biochemical functions, especially in mitochondria, and is used to study those functions.
Glycerides
GLYCEROL esterified with FATTY ACIDS.
Cardiolipins
Acidic phospholipids composed of two molecules of phosphatidic acid covalently linked to a molecule of glycerol. They occur primarily in mitochondrial inner membranes and in bacterial plasma membranes. They are the main antigenic components of the Wassermann-type antigen that is used in nontreponemal SYPHILIS SERODIAGNOSIS.
Mitochondria, Muscle
Mitochondria of skeletal and smooth muscle. It does not include myocardial mitochondria for which MITOCHONDRIA, HEART is available.
Cholesterol Ester Transfer Proteins
Proteins that bind to and transfer CHOLESTEROL ESTERS between LIPOPROTEINS such as LOW-DENSITY LIPOPROTEINS and HIGH-DENSITY LIPOPROTEINS.
Enzyme Inhibitors
Arachis hypogaea
A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.
Intracellular Membranes
Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
Acetyl-CoA C-Acetyltransferase
Hydroxybutyrates
Salts and esters of hydroxybutyric acid.
Multienzyme Complexes
Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.
Detergents
Cricetinae
Polyethylene Glycols
Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.
Plasmalogens
Cells, Cultured
Rats, Sprague-Dawley
Tritium
Tritium is an isotope of hydrogen (specifically, hydrogen-3) that contains one proton and two neutrons in its nucleus, making it radioactive with a half-life of about 12.3 years, and is used in various applications including nuclear research, illumination, and dating techniques due to its low energy beta decay.
Structure-Activity Relationship
Cell Membrane
Lipoproteins, VLDL
A class of lipoproteins of very light (0.93-1.006 g/ml) large size (30-80 nm) particles with a core composed mainly of TRIGLYCERIDES and a surface monolayer of PHOSPHOLIPIDS and CHOLESTEROL into which are imbedded the apolipoproteins B, E, and C. VLDL facilitates the transport of endogenously made triglycerides to extrahepatic tissues. As triglycerides and Apo C are removed, VLDL is converted to INTERMEDIATE-DENSITY LIPOPROTEINS, then to LOW-DENSITY LIPOPROTEINS from which cholesterol is delivered to the extrahepatic tissues.
Mortierella
A genus of zygomycetous fungi of the family Mortierellaceae, order MUCORALES. Its species are abundant in soil and can cause rare infections in humans and animals. Mortierella alpinais is used for production of arachidonic acid.
Sterols
Chondrodysplasia Punctata, Rhizomelic
An autosomal recessive form of CHONDRODYSPLASIA PUNCTATA characterized by defective plasmalogen biosynthesis and impaired peroxisomes. Patients have shortened proximal limbs and severely disturbed endochondral bone formation. The metabolic defects associated with the impaired peroxisomes are present only in the rhizomelic form of chondrodysplasia punctata. (From Scriver et al, Metabolic Basis of Inherited Disease, 6th ed, p1497)
Acyl-CoA Dehydrogenase
A flavoprotein oxidoreductase that has specificity for medium-chain fatty acids. It forms a complex with ELECTRON TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.
Deoxycholic Acid
A bile acid formed by bacterial action from cholate. It is usually conjugated with glycine or taurine. Deoxycholic acid acts as a detergent to solubilize fats for intestinal absorption, is reabsorbed itself, and is used as a choleretic and detergent.