Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-hydroxy-3-methylglutaryl-coenzyme A to yield MEVALONIC ACID.
Compounds that inhibit HMG-CoA reductases. They have been shown to directly lower cholesterol synthesis.
A fungal metabolite isolated from cultures of Aspergillus terreus. The compound is a potent anticholesteremic agent. It inhibits 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It also stimulates the production of low-density lipoprotein receptors in the liver.
Mevalonic acid is a crucial intermediate compound in the HMG-CoA reductase pathway, which is a metabolic route that produces cholesterol, other steroids, and isoprenoids in cells.
A derivative of LOVASTATIN and potent competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It may also interfere with steroid hormone production. Due to the induction of hepatic LDL RECEPTORS, it increases breakdown of LDL CHOLESTEROL.
7-carbon saturated monocarboxylic acids.
The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.
Azoles of one NITROGEN and two double bonds that have aromatic chemical properties.
Substances used to lower plasma CHOLESTEROL levels.
Glutarates are organic compounds, specifically carboxylic acids, that contain a five-carbon chain with two terminal carboxyl groups and a central methyl group, playing a role in various metabolic processes, including the breakdown of certain amino acids. They can also refer to their salts or esters. Please note that this definition is concise and may not cover all aspects of glutarates in depth.
A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).
Oxidoreductases that are specific for the reduction of NITRATES.
A strongly basic anion exchange resin whose main constituent is polystyrene trimethylbenzylammonium Cl(-) anion.
Coenzyme A is an essential coenzyme that plays a crucial role in various metabolic processes, particularly in the transfer and activation of acetyl groups in important biochemical reactions such as fatty acid synthesis and oxidation, and the citric acid cycle.
Ribonucleotide Reductases are enzymes that catalyze the conversion of ribonucleotides to deoxyribonucleotides, which is a crucial step in DNA synthesis and repair, utilizing a radical mechanism for this conversion.
An antilipemic fungal metabolite isolated from cultures of Nocardia autotrophica. It acts as a competitive inhibitor of HMG CoA reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES).
Cholesterol which is substituted by a hydroxy group in any position.
Steroids with a hydroxyl group at C-3 and most of the skeleton of cholestane. Additional carbon atoms may be present in the side chain. (IUPAC Steroid Nomenclature, 1987)
A FLAVOPROTEIN oxidoreductase that occurs both as a soluble enzyme and a membrane-bound enzyme due to ALTERNATIVE SPLICING of a single mRNA. The soluble form is present mainly in ERYTHROCYTES and is involved in the reduction of METHEMOGLOBIN. The membrane-bound form of the enzyme is found primarily in the ENDOPLASMIC RETICULUM and outer mitochondrial membrane, where it participates in the desaturation of FATTY ACIDS; CHOLESTEROL biosynthesis and drug metabolism. A deficiency in the enzyme can result in METHEMOGLOBINEMIA.
Phosphoric or pyrophosphoric acid esters of polyisoprenoids.
A group of enzymes that oxidize diverse nitrogenous substances to yield nitrite. (Enzyme Nomenclature, 1992) EC 1.
Catalyzes the oxidation of GLUTATHIONE to GLUTATHIONE DISULFIDE in the presence of NADP+. Deficiency in the enzyme is associated with HEMOLYTIC ANEMIA. Formerly listed as EC 1.6.4.2.
An enzyme that utilizes NADH or NADPH to reduce FLAVINS. It is involved in a number of biological processes that require reduced flavin for their functions such as bacterial bioluminescence. Formerly listed as EC 1.6.8.1 and EC 1.5.1.29.
A FLAVOPROTEIN enzyme that catalyzes the oxidation of THIOREDOXINS to thioredoxin disulfide in the presence of NADP+. It was formerly listed as EC 1.6.4.5
A flavoprotein that catalyzes the reduction of heme-thiolate-dependent monooxygenases and is part of the microsomal hydroxylating system. EC 1.6.2.4.
Eicosamethyl octacontanonadecasen-1-o1. Polyprenol found in animal tissues that contains about 20 isoprene residues, the one carrying the alcohol group being saturated.
Cell surface receptors for AUTOCRINE MOTILITY FACTOR, which is the secreted form of GLUCOSE-6-PHOSPHATE ISOMERASE. The receptor has an unusual composition in that it shares some structural similarities with G-PROTEIN-COUPLED RECEPTORS and functions as an ubiquitin protein ligase when internalized.
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)
An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC 1.18.1.2 was formerly listed as EC 1.6.7.1 and EC 1.6.99.4.
Chemical compounds derived from acids by the elimination of a molecule of water.
Cytochrome reductases are enzymes that catalyze the transfer of electrons from donor molecules to cytochromes in electron transport chains, playing a crucial role in cellular respiration and energy production within cells.
Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
An enzyme that catalyzes the synthesis of hydroxymethylglutaryl-CoA from acetyl-CoA and acetoacetyl-CoA. This is a key enzyme in steroid biosynthesis. This enzyme was formerly listed as EC 4.1.3.5.
A post-translational modification of proteins by the attachment of an isoprenoid to the C-terminal cysteine residue. The isoprenoids used, farnesyl diphosphate or geranylgeranyl diphosphate, are derived from the same biochemical pathway that produces cholesterol.
Fatty acids which are unsaturated in only one position.
The rate dynamics in chemical or physical systems.
Cholesterol present in food, especially in animal products.
An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.
A membrane-bound cytochrome P450 enzyme that catalyzes the 7-alpha-hydroxylation of CHOLESTEROL in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of BILE ACIDS.
A family of sterols commonly found in plants and plant oils. Alpha-, beta-, and gamma-isomers have been characterized.
A flavoprotein amine oxidoreductase that catalyzes the reversible conversion of 5-methyltetrahydrofolate to 5,10-methylenetetrahydrofolate. This enzyme was formerly classified as EC 1.1.1.171.
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.
A sterol regulatory element binding protein that regulates GENES involved in CHOLESTEROL synthesis and uptake.
Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)
An NAD-dependent enzyme that catalyzes the oxidation of nitrite to nitrate. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM and is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. It was formerly classified as EC 1.6.6.1.
Reductases that catalyze the reaction of peptide-L-methionine -S-oxide + thioredoxin to produce peptide-L-methionine + thioredoxin disulfide + H(2)O.
Two-ring crystalline hydrocarbons isolated from coal tar. They are used as intermediates in chemical synthesis, as insect repellents, fungicides, lubricants, preservatives, and, formerly, as topical antiseptics.
An enzyme of the oxidoreductase class that catalyzes the formation of 2'-deoxyribonucleotides from the corresponding ribonucleotides using NADPH as the ultimate electron donor. The deoxyribonucleoside diphosphates are used in DNA synthesis. (From Dorland, 27th ed) EC 1.17.4.1.
Receptors on the plasma membrane of nonhepatic cells that specifically bind LDL. The receptors are localized in specialized regions called coated pits. Hypercholesteremia is caused by an allelic genetic defect of three types: 1, receptors do not bind to LDL; 2, there is reduced binding of LDL; and 3, there is normal binding but no internalization of LDL. In consequence, entry of cholesterol esters into the cell is impaired and the intracellular feedback by cholesterol on 3-hydroxy-3-methylglutaryl CoA reductase is lacking.
Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.
A subclass of enzymes which includes all dehydrogenases acting on carbon-carbon bonds. This enzyme group includes all the enzymes that introduce double bonds into substrates by direct dehydrogenation of carbon-carbon single bonds.
NAD(P)H:(quinone acceptor) oxidoreductases. A family that includes three enzymes which are distinguished by their sensitivity to various inhibitors. EC 1.6.99.2 (NAD(P)H DEHYDROGENASE (QUINONE);) is a flavoprotein which reduces various quinones in the presence of NADH or NADPH and is inhibited by dicoumarol. EC 1.6.99.5 (NADH dehydrogenase (quinone)) requires NADH, is inhibited by AMP and 2,4-dinitrophenol but not by dicoumarol or folic acid derivatives. EC 1.6.99.6 (NADPH dehydrogenase (quinone)) requires NADPH and is inhibited by dicoumarol and folic acid derivatives but not by 2,4-dinitrophenol.

Induction of selected lipid metabolic enzymes and differentiation-linked structural proteins by air exposure in fetal rat skin explants. (1/1273)

The epidermal permeability barrier of premature infants matures rapidly following birth. Previous studies suggest that air exposure could contribute to this acceleration, because: (i) development of a structurally and functionally mature barrier accelerates when fetal rat skin explants are incubated at an air-medium interface, and (ii) occlusion with a water-impermeable membrane prevents this acceleration. To investigate further the effects of air exposure on epidermal barrier ontogenesis, we compared the activities of several key enzymes of lipid metabolism and gene expression of protein markers of epidermal differentiation in fetal rat skin explants grown immersed versus air exposed. The rate-limiting enzymes of cholesterol (HMG CoA reductase) and ceramide (serine palmitoyl transferase) synthesis were not affected. In contrast, the normal developmental increases in activities of glucosylceramide synthase and cholesterol sulfotransferase, responsible for the synthesis of glucosylceramides and cholesterol sulfate, respectively, were accelerated further by air exposure. Additionally, two enzymes required for the final stages of barrier maturation and essential for normal stratum corneum function, beta-glucocerebrosidase, which converts glucosylceramide to ceramide, and steroid sulfatase, which desulfates cholesterol sulfate, also increased with air exposure. Furthermore, filaggrin and loricrin mRNA levels, and filaggrin, loricrin, and involucrin protein levels all increased with air exposure. Finally, occlusion with a water-impermeable membrane prevented both the air-exposure-induced increase in lipid enzyme activity, and the expression of loricrin, filaggrin, and involucrin. Thus, air exposure stimulates selected lipid metabolic enzymes and the gene expression of key structural proteins in fetal epidermis, providing a biochemical basis for air-induced acceleration of permeability barrier maturation in premature infants.  (+info)

Lovastatin-induced proliferation inhibition and apoptosis in C6 glial cells. (2/1273)

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase is the rate-limiting enzyme in cholesterol biosynthesis. HMG-CoA reductase converts HMG-CoA to mevalonate, which is then converted into cholesterol or various isoprenoids through multiple enzymatic steps. In this study, we examined the cytotoxic effects of lovastatin, an HMG-CoA reductase inhibitor, in C6 glial cells. Lovastatin at concentrations higher than 10 microM suppressed cell proliferation and induced cell death, which were prevented completely by mevalonate (300 microM). The data from lactate dehydrogenase assay and fluorescence microscopic assay using Hoechst 33342 and propidium iodide showed that mevalonate at a concentration of 100 microM could prevent lovastatin-induced cell death, whereas it could not prevent lovastatin-induced inhibition of cell proliferation. These data suggest that the lovastatin-induced interruption of cell cycle transition was not sufficient to induce cell death in C6 glial cells. In the presence of lovastatin at concentrations higher than 10 microM, DNA laddering, the typical finding of apoptosis, was identified. Lovastatin-induced apoptosis was prevented by mevalonate (100 microM). Both cycloheximide (0.5 microgram/ml) and actinomycin D (0.1 microgram/ml) prevented lovastatin-induced DNA laddering. In this study, we demonstrated that the cytotoxic effects of lovastatin fall into two categories: suppression of cell growth and induction of apoptosis in C6 glial cells.  (+info)

Distribution of exogenous 25-hydroxycholesterol in Hep G2 cells between two different pools. (3/1273)

Binding of [26,27-(3)H]25-hydroxycholesterol (25HC) to human hepatoma Hep G2 cells was saturated within 120 min. Two intracellular pools of 25HC were identified in a pulse-chase experiment: (i) an exchangeable pool which was in dynamic equilibrium with 25HC in the medium (t(1/2) of reversible exchange 15 min) and (ii) an unexchangeable pool which remained in cells during incubation in medium containing LPDS. 25HC from the exchangeable pool inhibits cholesterol biosynthesis, decreases the HMG CoA reductase mRNA level and stimulates cholesterol acylation. 25HC from the unexchangeable pool was partially bound to cytosolic proteins and apparently utilized for metabolic transformation. Incubation of Hep G2 cells with [26,27-(3)H]25HC in the presence of a 30-fold molar excess of 3beta-hydroxy-5alpha-cholest-8(14)-en-15-one was found to cause (i) 2-fold decrease in the binding of [26,27-(3)H]25HC to cytosolic proteins (sedimentation constant of radioactive complex was 4-5 S) and (ii) the 35% inhibition of 25HC transformation to polar metabolites.  (+info)

ApoB100 secretion from HepG2 cells is decreased by the ACAT inhibitor CI-1011: an effect associated with enhanced intracellular degradation of ApoB. (4/1273)

The concept that hepatic cholesteryl ester (CE) mass and the rate of cholesterol esterification regulate hepatocyte assembly and secretion of apoB-containing lipoproteins remains controversial. The present study was carried out in HepG2 cells to correlate the rate of cholesterol esterification and CE mass with apoB secretion by CI-1011, an acyl CoA:cholesterol acyltransferase (ACAT) inhibitor that is known to decrease apoB secretion, in vivo, in miniature pigs. HepG2 cells were incubated with CI-1011 (10 nmol/L, 1 micromol/L, and 10 micromol/L) for 24 hours. ApoB secretion into media was decreased by 25%, 27%, and 43%, respectively (P<0.0012). CI-1011 (10 micromol/L) inhibited HepG2 cell ACAT activity by 79% (P<0.002) and cellular CE mass by 32% (P<0.05). In contrast, another ACAT inhibitor, DuP 128 (10 micromol/L), decreased cellular ACAT activity and CE mass by 85% (P<0.002) and 42% (P=0.01), respectively, but had no effect on apoB secretion into media. To characterize the reduction in apoB secretion by CI-1011, pulse-chase experiments were performed and analyzed by multicompartmental modelling using SAAM II. CI-1011 did not affect the synthesis of apoB or albumin. However, apoB secretion into the media was decreased by 42% (P=0.019). Intracellular apoB degradation increased proportionately (P=0.019). The secretion of albumin and cellular reuptake of labeled lipoproteins were unchanged. CI-1011 and DuP 128 did not affect apoB mRNA concentrations. These results show that CI-1011 decreases apoB secretion by a mechanism that involves an enhanced intracellular degradation of apoB. This study demonstrates that ACAT inhibitors can exert differential effects on apoB secretion from HepG2 cells that do not reflect their efficacy in inhibiting cholesterol esterification.  (+info)

Select 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors vary in their ability to reduce egg yolk cholesterol levels in laying hens through alteration of hepatic cholesterol biosynthesis and plasma VLDL composition. (5/1273)

The inability to markedly attenuate cholesterol levels in chicken eggs has led to speculation that cholesterol is essential for yolk formation and that egg production would cease when yolk cholesterol deposition was inadequate for embryonic survival. However, this critical level hypothesis remains unproven. Here, we determine the relative responsiveness of laying hens to three select inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR), the rate-limiting enzyme of cholesterol biosynthesis. A control diet, either alone or supplemented with one of two dietary levels (0.03 or 0.06%) of atorvastatin, lovastatin, or simvastatin, was fed to White Leghorn hens for 5 wk. Liver cholesterol concentrations (mg/g tissue) were decreased (P 0.05), and 22% (P 0.05), and -3% (P > 0.05)], was much less affected. We concluded that cholesterol per se may not be an obligatory component for yolk formation in chickens and, as such, may be amenable to further pharmacological manipulation  (+info)

Two SNF1-related protein kinases from spinach leaf phosphorylate and inactivate 3-hydroxy-3-methylglutaryl-coenzyme A reductase, nitrate reductase, and sucrose phosphate synthase in vitro. (6/1273)

We resolved from spinach (Spinacia oleracea) leaf extracts four Ca2+-independent protein kinase activities that phosphorylate the AMARAASAAALARRR (AMARA) and HMRSAMSGLHLVKRR (SAMS) peptides, originally designed as specific substrates for mammalian AMP-activated protein kinase and its yeast homolog, SNF1. The two major activities, HRK-A and HRK-C (3-hydroxy-3-methylglutaryl-coenzyme A reductase kinase A and C) were extensively purified and shown to be members of the plant SnRK1 (SNF1-related protein kinase 1) family using the following criteria: (a) They contain 58-kD polypeptides that cross-react with an antibody against a peptide sequence characteristic of the SnRK1 family; (b) they have similar native molecular masses and specificity for peptide substrates to mammalian AMP-activated protein kinase and the cauliflower homolog; (c) they are inactivated by homogeneous protein phosphatases and can be reactivated using the mammalian upstream kinase; and (d) they phosphorylate 3-hydroxy-3-methylglutaryl-coenzyme A reductase from Arabidopsis at the inactivating site, serine (Ser)-577. We propose that HRK-A and HRK-C represent either distinct SnRK1 isoforms or the same catalytic subunit complexed with different regulatory subunits. Both kinases also rapidly phosphorylate nitrate reductase purified from spinach, which is associated with inactivation of the enzyme that is observed only in the presence of 14-3-3 protein, a characteristic of phosphorylation at Ser-543. Both kinases also inactivate spinach sucrose phosphate synthase via phosphorylation at Ser-158. The SNF1-related kinases therefore potentially regulate several major biosynthetic pathways in plants: isoprenoid synthesis, sucrose synthesis, and nitrogen assimilation for the synthesis of amino acids and nucleotides.  (+info)

High plasma cholesterol in drug-induced cholestasis is associated with enhanced hepatic cholesterol synthesis. (7/1273)

In alpha-naphthylisothiocyanate-treated mice, plasma phospholipid (PL) levels were elevated 10- and 13-fold at 48 and 168 h, respectively, whereas free cholesterol (FC) levels increased between 48 h (17-fold) and 168 h (39-fold). Nearly all of these lipids were localized to lipoprotein X-like particles in the low-density lipoprotein density range. The PL fatty acyl composition was indicative of biliary origin. Liver cholesterol and PL content were near normal at all time points. Hepatic hydroxymethylglutaryl CoA reductase activity was increased sixfold at 48 h, and cholesterol 7alpha-hydroxylase activity was decreased by approximately 70% between 24 and 72 h. These findings suggest a metabolic basis for the appearance of abnormal plasma lipoproteins during cholestasis. Initially, PL and bile acids appear in plasma where they serve to promote the efflux of cholesterol from hepatic cell membranes. Hepatic cholesterol synthesis is then likely stimulated in the response to the depletion of hepatic cell membranes of cholesterol. We speculate that the enhanced synthesis of cholesterol and impaired conversion to bile acids, particularly during the early phase of drug response, contribute to the accumulation of FC in the plasma.  (+info)

Plasma and hepatic cholesterol and hepatic activities of 3-hydroxy-3-methyl-glutaryl-CoA reductase and acyl CoA: cholesterol transferase are lower in rats fed citrus peel extract or a mixture of citrus bioflavonoids. (8/1273)

The cholesterol-lowering effects of tangerine peel extract and a mixture of two citrus flavonoids were tested. Male rats were fed a 1 g/100 g high-cholesterol diet for 42 d with supplements of either tangerine-peel extract or a mixture of naringin and hesperidin (0.5 g/100 g) to study the effects of plasma and hepatic lipids, hepatic enzyme activities, and the excretion of fecal neutral sterols. Both the tangerine-peel extract and mixture of two flavonoids significantly lowered the levels (mean +/- SE) of plasma (2.44 +/- 0. 59 and 2.42 +/- 0.31 mmol/L, vs. 3.80 +/- 0.28 mmol/L, P < 0.05), hepatic cholesterol (0.143 +/- 0.017 and 0.131 +/- 0.010 mmol/g vs. 0.181 +/- 0.003 mmol/g, P < 0.05), and hepatic triglycerides (0.069 +/- 0.007 and 0.075 +/- 0.006 mmol/g vs. 0.095 +/- 0.002 mmol/g, P < 0.05) compared to those of the control. The 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase (1565.0 +/- 106. 0 pmol. min-1. mg protein-1 and 1783.0 +/- 282 pmol. min-1. mg protein-1 vs. 2487.0 +/- 210.0 pmol. min-1. mg protein-1, P < 0.05) and acyl CoA: cholesterol O-acyltransferase (ACAT) activities (548.0 +/- 65.0 and 615.0 +/- 80.0 pmol. min-1. mg protein-1 vs. 806.0 +/- 105.0 pmol. min-1. mg protein-1, P < 0.05) were significantly lower in the experimental groups than in the control. These supplements also substantially reduced the excretion of fecal neutral sterols compared to the control (211.1 +/- 26.7 and 208.2 +/- 31.6 mg/d vs. 521.9 +/- 53.9 mg/d). The inhibition of HMG-CoA reductase and ACAT activities resulting from the supplementation of either tangerine-peel extract or a combination of its bioflavonoids could account for the decrease in fecal neutral sterol that appears to compensate for the decreased cholesterol biosynthesis in the liver.  (+info)

Hydroxymethylglutaryl CoA (HMG-CoA) reductase is an enzyme that plays a crucial role in the synthesis of cholesterol in the body. It is found in the endoplasmic reticulum of cells and catalyzes the conversion of HMG-CoA to mevalonic acid, which is a key rate-limiting step in the cholesterol biosynthetic pathway.

The reaction catalyzed by HMG-CoA reductase is as follows:

HMG-CoA + 2 NADPH + 2 H+ → mevalonic acid + CoA + 2 NADP+

This enzyme is the target of statin drugs, which are commonly prescribed to lower cholesterol levels in the treatment of cardiovascular diseases. Statins work by inhibiting HMG-CoA reductase, thereby reducing the production of cholesterol in the body.

Hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors, also known as statins, are a class of cholesterol-lowering medications. They work by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol in the liver. By blocking this enzyme, the liver is stimulated to take up more low-density lipoprotein (LDL) cholesterol from the bloodstream, leading to a decrease in LDL cholesterol levels and a reduced risk of cardiovascular disease.

Examples of HMG-CoA reductase inhibitors include atorvastatin, simvastatin, pravastatin, rosuvastatin, and fluvastatin. These medications are commonly prescribed to individuals with high cholesterol levels, particularly those who are at risk for or have established cardiovascular disease.

It's important to note that while HMG-CoA reductase inhibitors can be effective in reducing LDL cholesterol levels and the risk of cardiovascular events, they should be used as part of a comprehensive approach to managing high cholesterol, which may also include lifestyle modifications such as dietary changes, exercise, and weight management.

Lovastatin is a medication that belongs to a class of drugs called statins, which are used to lower cholesterol levels in the blood. It works by inhibiting HMG-CoA reductase, an enzyme that plays a crucial role in the production of cholesterol in the body. By reducing the amount of cholesterol produced in the liver, lovastatin helps to decrease the levels of low-density lipoprotein (LDL) or "bad" cholesterol and triglycerides in the blood, while increasing the levels of high-density lipoprotein (HDL) or "good" cholesterol.

Lovastatin is available in both immediate-release and extended-release forms, and it is typically taken orally once or twice a day, depending on the dosage prescribed by a healthcare provider. Common side effects of lovastatin include headache, nausea, diarrhea, and muscle pain, although more serious side effects such as liver damage and muscle weakness are possible, particularly at higher doses.

It is important to note that lovastatin should not be taken by individuals with active liver disease or by those who are pregnant or breastfeeding. Additionally, it may interact with certain other medications, so it is essential to inform a healthcare provider of all medications being taken before starting lovastatin therapy.

Mevalonic acid is not a term that is typically used in medical definitions, but rather it is a biochemical concept. Mevalonic acid is a key intermediate in the biosynthetic pathway for cholesterol and other isoprenoids. It is formed from 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) by the enzyme HMG-CoA reductase, which is the target of cholesterol-lowering drugs known as statins.

In a medical context, mevalonic acid may be mentioned in relation to certain rare genetic disorders, such as mevalonate kinase deficiency (MKD) or hyperimmunoglobulinemia D and periodic fever syndrome (HIDS), which are caused by mutations in the gene encoding mevalonate kinase, an enzyme involved in the metabolism of mevalonic acid. These conditions can cause recurrent fevers, rashes, joint pain, and other symptoms.

Simvastatin is a medication that belongs to a class of drugs called statins, which are used to lower cholesterol levels in the blood. It works by inhibiting HMG-CoA reductase, an enzyme that plays a key role in the production of cholesterol in the body. By reducing the amount of cholesterol produced by the liver, simvastatin helps to lower the levels of LDL (low-density lipoprotein) or "bad" cholesterol and triglycerides in the blood, while increasing HDL (high-density lipoprotein) or "good" cholesterol.

Simvastatin is used to prevent cardiovascular diseases such as heart attacks and strokes in individuals with high cholesterol levels, particularly those who have other risk factors such as diabetes, hypertension, or a history of smoking. It is available in various strengths and forms, and is typically taken orally once a day, usually in the evening.

Like all medications, simvastatin can cause side effects, ranging from mild to severe. Common side effects include headache, muscle pain, and gastrointestinal symptoms such as nausea, constipation, or diarrhea. Rare but serious side effects may include liver damage, muscle breakdown (rhabdomyolysis), and increased risk of diabetes. It is important to follow the dosage instructions carefully and inform your healthcare provider of any pre-existing medical conditions or medications you are taking, as these may affect the safety and efficacy of simvastatin.

Heptanoic acid, also known as enanthic acid, is an organic compound with the formula CH3(CH2)5COOH. It is a fatty acid with a 7-carbon chain, and it is a colorless liquid that is slightly soluble in water and fully miscible with ether and ethanol.

Heptanoic acid is not typically considered a medical term, as it is not a substance that is directly related to human health or disease. However, like other fatty acids, heptanoic acid can be metabolized in the body for energy and used in various physiological processes. Abnormal levels of certain fatty acids, including heptanoic acid, may be associated with various medical conditions, such as metabolic disorders or genetic diseases that affect fatty acid metabolism.

It's important to note that Heptanoic Acid is not a common term in medicine, and it's more related to chemistry and biochemistry fields.

Cholesterol is a type of lipid (fat) molecule that is an essential component of cell membranes and is also used to make certain hormones and vitamins in the body. It is produced by the liver and is also obtained from animal-derived foods such as meat, dairy products, and eggs.

Cholesterol does not mix with blood, so it is transported through the bloodstream by lipoproteins, which are particles made up of both lipids and proteins. There are two main types of lipoproteins that carry cholesterol: low-density lipoproteins (LDL), also known as "bad" cholesterol, and high-density lipoproteins (HDL), also known as "good" cholesterol.

High levels of LDL cholesterol in the blood can lead to a buildup of cholesterol in the walls of the arteries, increasing the risk of heart disease and stroke. On the other hand, high levels of HDL cholesterol are associated with a lower risk of these conditions because HDL helps remove LDL cholesterol from the bloodstream and transport it back to the liver for disposal.

It is important to maintain healthy levels of cholesterol through a balanced diet, regular exercise, and sometimes medication if necessary. Regular screening is also recommended to monitor cholesterol levels and prevent health complications.

"Pyrroles" is not a medical term in and of itself, but "pyrrole" is an organic compound that contains one nitrogen atom and four carbon atoms in a ring structure. In the context of human health, "pyrroles" often refers to a group of compounds called pyrrol derivatives or pyrrole metabolites.

In clinical settings, "pyrroles" is sometimes used to refer to a urinary metabolite called "pyrrole-protein conjugate," which contains a pyrrole ring and is excreted in the urine. Elevated levels of this compound have been associated with certain psychiatric and behavioral disorders, such as schizophrenia and mood disorders. However, the relationship between pyrroles and these conditions is not well understood, and more research is needed to establish a clear medical definition or diagnostic criteria for "pyrrole disorder" or "pyroluria."

Anticholesteremic agents are a class of medications that are used to lower the levels of cholesterol and other fats called lipids in the blood. These medications work by reducing the production of cholesterol in the body, increasing the removal of cholesterol from the bloodstream, or preventing the absorption of cholesterol in the digestive tract.

There are several types of anticholesteremic agents, including:

1. Statins: These medications work by blocking a liver enzyme that is necessary for the production of cholesterol. Examples of statins include atorvastatin, simvastatin, and rosuvastatin.
2. Bile acid sequestrants: These medications bind to bile acids in the digestive tract and prevent them from being reabsorbed into the bloodstream. This causes the liver to produce more bile acids, which in turn lowers cholesterol levels. Examples of bile acid sequestrants include cholestyramine and colesevelam.
3. Nicotinic acid: Also known as niacin, this medication works by reducing the production of very low-density lipoproteins (VLDL) in the liver, which are a major source of bad cholesterol.
4. Fibrates: These medications work by increasing the removal of cholesterol from the bloodstream and reducing the production of VLDL in the liver. Examples of fibrates include gemfibrozil and fenofibrate.
5. PCSK9 inhibitors: These are a newer class of medications that work by blocking the action of a protein called PCSK9, which helps regulate the amount of cholesterol in the blood. By blocking PCSK9, these medications increase the number of LDL receptors on the surface of liver cells, which leads to increased removal of LDL from the bloodstream.

Anticholesteremic agents are often prescribed for people who have high cholesterol levels and are at risk for heart disease or stroke. By lowering cholesterol levels, these medications can help reduce the risk of heart attack, stroke, and other cardiovascular events.

Glutarates are compounds that contain a glutaric acid group. Glutaric acid is a carboxylic acid with a five-carbon chain and two carboxyl groups at the 1st and 5th carbon positions. Glutarates can be found in various substances, including certain foods and medications.

In a medical context, glutarates are sometimes used as ingredients in pharmaceutical products. For example, sodium phenylbutyrate, which is a salt of phenylbutyric acid and butyric acid, contains a glutaric acid group and is used as a medication to treat urea cycle disorders.

Glutarates can also be found in some metabolic pathways in the body, where they play a role in energy production and other biochemical processes. However, abnormal accumulation of glutaric acid or its derivatives can lead to certain medical conditions, such as glutaric acidemia type I, which is an inherited disorder of metabolism that can cause neurological symptoms and other health problems.

Alcohol oxidoreductases are a class of enzymes that catalyze the oxidation of alcohols to aldehydes or ketones, while reducing nicotinamide adenine dinucleotide (NAD+) to NADH. These enzymes play an important role in the metabolism of alcohols and other organic compounds in living organisms.

The most well-known example of an alcohol oxidoreductase is alcohol dehydrogenase (ADH), which is responsible for the oxidation of ethanol to acetaldehyde in the liver during the metabolism of alcoholic beverages. Other examples include aldehyde dehydrogenases (ALDH) and sorbitol dehydrogenase (SDH).

These enzymes are important targets for the development of drugs used to treat alcohol use disorder, as inhibiting their activity can help to reduce the rate of ethanol metabolism and the severity of its effects on the body.

Nitrate reductases are a group of enzymes that catalyze the reduction of nitrate (NO3-) to nitrite (NO2-). This process is an essential part of the nitrogen cycle, where nitrate serves as a terminal electron acceptor in anaerobic respiration for many bacteria and archaea. In plants, this enzyme plays a crucial role in nitrogen assimilation by reducing nitrate to ammonium (NH4+), which can then be incorporated into organic compounds. Nitrate reductases require various cofactors, such as molybdenum, heme, and/or FAD, for their activity. There are three main types of nitrate reductases: membrane-bound (which use menaquinol as an electron donor), cytoplasmic (which use NADH or NADPH as an electron donor), and assimilatory (which also use NADH or NADPH as an electron donor).

Cholestyramine resin is a medication used to treat high levels of cholesterol in the blood. It is a type of drug called a bile acid sequestrant, which works by binding to bile acids in the digestive system and preventing them from being reabsorbed into the body. This leads to an increased removal of cholesterol from the body, which can help lower the levels of cholesterol in the blood.

Cholestyramine resin is available as a powder that is mixed with water or other fluids and taken by mouth. It may be used alone or in combination with other medications to treat high cholesterol. In addition to its use for lowering cholesterol, cholestyramine resin may also be used to treat itching associated with partial biliary obstruction (blockage of the bile ducts) and to reduce the absorption of certain drugs, such as digitalis and thyroid hormones.

It is important to follow the instructions of a healthcare provider when taking cholestyramine resin, as the medication can interfere with the absorption of other medications and nutrients. It may also cause gastrointestinal side effects, such as constipation, bloating, and gas.

Coenzyme A, often abbreviated as CoA or sometimes holo-CoA, is a coenzyme that plays a crucial role in several important chemical reactions in the body, particularly in the metabolism of carbohydrates, fatty acids, and amino acids. It is composed of a pantothenic acid (vitamin B5) derivative called pantothenate, an adenosine diphosphate (ADP) molecule, and a terminal phosphate group.

Coenzyme A functions as a carrier molecule for acetyl groups, which are formed during the breakdown of carbohydrates, fatty acids, and some amino acids. The acetyl group is attached to the sulfur atom in CoA, forming acetyl-CoA, which can then be used as a building block for various biochemical pathways, such as the citric acid cycle (Krebs cycle) and fatty acid synthesis.

In summary, Coenzyme A is a vital coenzyme that helps facilitate essential metabolic processes by carrying and transferring acetyl groups in the body.

Ribonucleotide Reductases (RNRs) are enzymes that play a crucial role in DNA synthesis and repair. They catalyze the conversion of ribonucleotides to deoxyribonucleotides, which are the building blocks of DNA. This process involves the reduction of the 2'-hydroxyl group of the ribose sugar to a hydrogen, resulting in the formation of deoxyribose.

RNRs are highly regulated and exist in various forms across different species. They are divided into three classes (I, II, and III) based on their structure, mechanism, and cofactor requirements. Class I RNRs are further divided into two subclasses (Ia and Ib), which differ in their active site architecture and regulation.

Class Ia RNRs, found in eukaryotes and some bacteria, contain a stable tyrosyl radical that acts as the catalytic center for hydrogen abstraction. Class Ib RNRs, found in many bacteria, use a pair of iron centers to perform the same function. Class II RNRs are present in some bacteria and archaea and utilize adenosine triphosphate (ATP) as a cofactor for reduction. Class III RNRs, found in anaerobic bacteria and archaea, use a unique mechanism involving a radical S-adenosylmethionine (SAM) cofactor to facilitate the reduction reaction.

RNRs are essential for DNA replication and repair, and their dysregulation has been linked to various diseases, including cancer and neurodegenerative disorders. Therefore, understanding the structure, function, and regulation of RNRs is of great interest in biochemistry, molecular biology, and medicine.

Pravastatin is a medication that belongs to a class of drugs called statins, which are used to lower cholesterol levels in the blood. Specifically, pravastatin works by inhibiting HMG-CoA reductase, an enzyme involved in the production of cholesterol in the liver. By reducing the amount of cholesterol produced, pravastatin helps to decrease the levels of low-density lipoprotein (LDL) or "bad" cholesterol and increase the levels of high-density lipoprotein (HDL) or "good" cholesterol in the blood.

Pravastatin is used to prevent cardiovascular diseases such as heart attacks and strokes, particularly in people with high cholesterol levels, diabetes, or other risk factors for heart disease. It is available in tablet form and is typically taken once daily. As with any medication, pravastatin should be taken under the supervision of a healthcare provider, who will determine the appropriate dosage based on the individual's medical history and current health status.

Hydroxycholesterols are a type of sterol that is formed in the body when cholesterol, a steroid alcohol, undergoes hydroxylation. This means that one or more hydroxyl groups (-OH) are added to the cholesterol molecule. There are several different types of hydroxycholesterols, including 24-hydroxycholesterol, 25-hydroxycholesterol, and 27-hydroxycholesterol, among others. These compounds play important roles in various physiological processes, such as regulating cholesterol metabolism and contributing to the formation of bile acids. They have also been studied for their potential involvement in atherosclerosis, Alzheimer's disease, and other health conditions.

Sterols are a type of organic compound that is derived from steroids and found in the cell membranes of organisms. In animals, including humans, cholesterol is the most well-known sterol. Sterols help to maintain the structural integrity and fluidity of cell membranes, and they also play important roles as precursors for the synthesis of various hormones and other signaling molecules. Phytosterols are plant sterols that have been shown to have cholesterol-lowering effects in humans when consumed in sufficient amounts.

Polyisoprenyl phosphates are a type of organic compound that play a crucial role in the biosynthesis of various essential biomolecules in cells. They are formed by the addition of isoprene units, which are five-carbon molecules with a branched structure, to a phosphate group.

In medical terms, polyisoprenyl phosphates are primarily known for their role as intermediates in the biosynthesis of dolichols and farnesylated proteins. Dolichols are long-chain isoprenoids that function as lipid carriers in the synthesis of glycoproteins, which are proteins that contain carbohydrate groups attached to them. Farnesylated proteins, on the other hand, are proteins that have been modified with a farnesyl group, which is a 15-carbon isoprenoid. This modification plays a role in the localization and function of certain proteins within the cell.

Abnormalities in the biosynthesis of polyisoprenyl phosphates and their downstream products have been implicated in various diseases, including cancer, neurological disorders, and genetic syndromes. Therefore, understanding the biology and regulation of these compounds is an active area of research with potential therapeutic implications.

Nitrite reductases are a group of enzymes that catalyze the reduction of nitrite (NO2-) to nitric oxide (NO). This reaction is an important part of the nitrogen cycle, particularly in denitrification and dissimilatory nitrate reduction to ammonium (DNRA) processes. Nitrite reductases can be classified into two main types based on their metal co-factors: copper-containing nitrite reductases (CuNiRs) and cytochrome cd1 nitrite reductases. CuNiRs are typically found in bacteria and fungi, while cytochrome cd1 nitrite reductases are primarily found in bacteria. These enzymes play a crucial role in the global nitrogen cycle and have potential implications for environmental and medical research.

Glutathione reductase (GR) is an enzyme that plays a crucial role in maintaining the cellular redox state. The primary function of GR is to reduce oxidized glutathione (GSSG) to its reduced form (GSH), which is an essential intracellular antioxidant. This enzyme utilizes nicotinamide adenine dinucleotide phosphate (NADPH) as a reducing agent in the reaction, converting it to NADP+. The medical definition of Glutathione Reductase is:

Glutathione reductase (GSR; EC 1.8.1.7) is a homodimeric flavoprotein that catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) in the presence of NADPH as a cofactor. This enzyme is essential for maintaining the cellular redox balance and protecting cells from oxidative stress by regenerating the active form of glutathione, a vital antioxidant and detoxifying agent.

Flavin Mononucleotide (FMN) Reductase is an enzyme that catalyzes the reduction of FMN to FMNH2 using NADH or NADPH as an electron donor. This enzyme plays a crucial role in the electron transport chain and is involved in various redox reactions within the cell. It is found in many organisms, including bacteria, fungi, plants, and animals. In humans, FMN Reductase is encoded by the RIBFLR gene and is primarily located in the mitochondria. Defects in this enzyme can lead to various metabolic disorders.

Thioredoxin-disulfide reductase (Txnrd, TrxR) is an enzyme that belongs to the pyridine nucleotide-disulfide oxidoreductase family. It plays a crucial role in maintaining the intracellular redox balance by reducing disulfide bonds in proteins and keeping them in their reduced state. This enzyme utilizes NADPH as an electron donor to reduce thioredoxin (Trx), which then transfers its electrons to various target proteins, thereby regulating their activity, protein folding, and antioxidant defense mechanisms.

Txnrd is essential for several cellular processes, including DNA synthesis, gene expression, signal transduction, and protection against oxidative stress. Dysregulation of Txnrd has been implicated in various pathological conditions, such as cancer, neurodegenerative diseases, and inflammatory disorders. Therefore, understanding the function and regulation of this enzyme is of great interest for developing novel therapeutic strategies.

NADPH-ferrihemoprotein reductase, also known as diaphorase or NO synthase reductase, is an enzyme that catalyzes the reduction of ferrihemoproteins using NADPH as a reducing cofactor. This reaction plays a crucial role in various biological processes such as the detoxification of certain compounds and the regulation of cellular signaling pathways.

The systematic name for this enzyme is NADPH:ferrihemoprotein oxidoreductase, and it belongs to the family of oxidoreductases that use NADH or NADPH as electron donors. The reaction catalyzed by this enzyme can be represented as follows:

NADPH + H+ + ferrihemoprotein ↔ NADP+ + ferrohemoprotein

In this reaction, the ferric (FeIII) form of hemoproteins is reduced to its ferrous (FeII) form by accepting electrons from NADPH. This enzyme is widely distributed in various tissues and organisms, including bacteria, fungi, plants, and animals. It has been identified as a component of several multi-enzyme complexes involved in different metabolic pathways, such as nitric oxide synthase (NOS) and cytochrome P450 reductase.

In summary, NADPH-ferrihemoprotein reductase is an essential enzyme that catalyzes the reduction of ferrihemoproteins using NADPH as a reducing agent, playing a critical role in various biological processes and metabolic pathways.

Dolichol is a type of lipid molecule that is involved in the process of protein glycosylation within the endoplasmic reticulum of eukaryotic cells. Glycosylation is the attachment of sugar molecules to proteins, and it plays a crucial role in various biological processes such as protein folding, trafficking, and cell-cell recognition.

Dolichols are long-chain polyisoprenoid alcohols that serve as carriers for the sugars during glycosylation. They consist of a hydrophobic tail made up of many isoprene units and a hydrophilic head group. The dolichol molecule is first activated by the addition of a diphosphate group to its terminal end, forming dolichyl pyrophosphate.

The sugars that will be attached to the protein are then transferred from their nucleotide sugar donors onto the dolichyl pyrophosphate carrier, creating a dolichol-linked oligosaccharide. This oligosaccharide is then transferred en bloc to the target protein in a process called "oligosaccharyltransferase" (OST) reaction.

Defects in dolichol biosynthesis or function can lead to various genetic disorders, such as congenital disorders of glycosylation (CDG), which are characterized by abnormal protein glycosylation and a wide range of clinical manifestations, including developmental delay, neurological impairment, and multi-systemic involvement.

Autocrine motility factor (AMF) receptors are cell surface proteins that bind to autocrine motility factor, a cytokine produced and released by certain types of cancer cells. The binding of AMF to its receptor activates signaling pathways within the same cell that produces it, leading to changes in cell behavior such as increased motility and invasiveness. This process is known as autocrine signaling and plays a role in tumor progression and metastasis.

The AMF receptor has been identified as the product of the gene for the insulin-like growth factor I receptor (IGF1R), which is a tyrosine kinase receptor that regulates cell growth, differentiation, and survival. The activation of the IGF1R by AMF leads to the activation of downstream signaling pathways such as the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt pathways, which promote cell motility and invasion.

In summary, Autocrine Motility Factor (AMF) receptors are a type of cell surface proteins that bind to AMF, leading to the activation of signaling pathways within the same cell that produces it, promoting changes in cell behavior such as increased motility and invasiveness, which play a role in tumor progression and metastasis.

Oxidoreductases are a class of enzymes that catalyze oxidation-reduction reactions, which involve the transfer of electrons from one molecule (the reductant) to another (the oxidant). These enzymes play a crucial role in various biological processes, including energy production, metabolism, and detoxification.

The oxidoreductase-catalyzed reaction typically involves the donation of electrons from a reducing agent (donor) to an oxidizing agent (acceptor), often through the transfer of hydrogen atoms or hydride ions. The enzyme itself does not undergo any permanent chemical change during this process, but rather acts as a catalyst to lower the activation energy required for the reaction to occur.

Oxidoreductases are classified and named based on the type of electron donor or acceptor involved in the reaction. For example, oxidoreductases that act on the CH-OH group of donors are called dehydrogenases, while those that act on the aldehyde or ketone groups are called oxidases. Other examples include reductases, peroxidases, and catalases.

Understanding the function and regulation of oxidoreductases is important for understanding various physiological processes and developing therapeutic strategies for diseases associated with impaired redox homeostasis, such as cancer, neurodegenerative disorders, and cardiovascular disease.

Ferredoxin-NADP Reductase (FDNR) is an enzyme that catalyzes the electron transfer from ferredoxin to NADP+, reducing it to NADPH. This reaction plays a crucial role in several metabolic pathways, including photosynthesis and nitrogen fixation.

In photosynthesis, FDNR is located in the stroma of chloroplasts and receives electrons from ferredoxin, which is reduced by photosystem I. The enzyme then transfers these electrons to NADP+, generating NADPH, which is used in the Calvin cycle for carbon fixation.

In nitrogen fixation, FDNR is found in the nitrogen-fixing bacteria and receives electrons from ferredoxin, which is reduced by nitrogenase. The enzyme then transfers these electrons to NADP+, generating NADPH, which is used in the reduction of nitrogen gas (N2) to ammonia (NH3).

FDNR is a flavoprotein that contains a FAD cofactor and an iron-sulfur cluster. The enzyme catalyzes the electron transfer through a series of conformational changes that bring ferredoxin and NADP+ in close proximity, allowing for efficient electron transfer.

Anhydrides are chemical compounds that form when a single molecule of water is removed from an acid, resulting in the formation of a new compound. The term "anhydride" comes from the Greek words "an," meaning without, and "hydor," meaning water.

In organic chemistry, anhydrides are commonly formed by the removal of water from a carboxylic acid. For example, when acetic acid (CH3COOH) loses a molecule of water, it forms acetic anhydride (CH3CO)2O. Acetic anhydride is a reactive compound that can be used to introduce an acetyl group (-COCH3) into other organic compounds.

Inorganic anhydrides are also important in chemistry and include compounds such as sulfur trioxide (SO3), which is an anhydride of sulfuric acid (H2SO4). Sulfur trioxide can react with water to form sulfuric acid, making it a key intermediate in the production of this important industrial chemical.

It's worth noting that some anhydrides can be hazardous and may require special handling and safety precautions.

Cytochrome reductases are a group of enzymes that play a crucial role in the electron transport chain, a process that occurs in the mitochondria of cells and is responsible for generating energy in the form of ATP (adenosine triphosphate). Specifically, cytochrome reductases are responsible for transferring electrons from one component of the electron transport chain to another, specifically to cytochromes.

There are several types of cytochrome reductases, including NADH dehydrogenase (also known as Complex I), succinate dehydrogenase (also known as Complex II), and ubiquinone-cytochrome c reductase (also known as Complex III). These enzymes help to facilitate the flow of electrons through the electron transport chain, which is essential for the production of ATP and the maintenance of cellular homeostasis.

Defects in cytochrome reductases can lead to a variety of mitochondrial diseases, which can affect multiple organ systems and may be associated with symptoms such as muscle weakness, developmental delays, and cardiac dysfunction.

Microsomes, liver refers to a subcellular fraction of liver cells (hepatocytes) that are obtained during tissue homogenization and subsequent centrifugation. These microsomal fractions are rich in membranous structures known as the endoplasmic reticulum (ER), particularly the rough ER. They are involved in various important cellular processes, most notably the metabolism of xenobiotics (foreign substances) including drugs, toxins, and carcinogens.

The liver microsomes contain a variety of enzymes, such as cytochrome P450 monooxygenases, that are crucial for phase I drug metabolism. These enzymes help in the oxidation, reduction, or hydrolysis of xenobiotics, making them more water-soluble and facilitating their excretion from the body. Additionally, liver microsomes also host other enzymes involved in phase II conjugation reactions, where the metabolites from phase I are further modified by adding polar molecules like glucuronic acid, sulfate, or acetyl groups.

In summary, liver microsomes are a subcellular fraction of liver cells that play a significant role in the metabolism and detoxification of xenobiotics, contributing to the overall protection and maintenance of cellular homeostasis within the body.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

Hydroxymethylglutaryl-CoA Synthase (HMG-CoA Synthase) is a key enzyme in the cholesterol biosynthesis pathway. It catalyzes the reaction of acetoacetyl-CoA and acetyl-CoA to form HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A), which is a crucial intermediate in the synthesis of cholesterol, ketone bodies, and other isoprenoids.

There are two isoforms of this enzyme: HMG-CoA synthase 1 (HMGCS1) and HMG-CoA synthase 2 (HMGCS2). HMGCS1 is primarily expressed in the liver and is involved in cholesterol synthesis, while HMGCS2 is mainly found in the brain, kidney, and liver, where it plays a role in ketone body synthesis during periods of fasting or low-carbohydrate diets.

Defects in HMG-CoA synthase can lead to metabolic disorders, such as hypocholesterolemia (low cholesterol levels) and hyperketonemia (elevated ketone bodies). Additionally, inhibitors of HMG-CoA synthase are used as cholesterol-lowering drugs, known as statins, to treat conditions like hyperlipidemia and prevent cardiovascular diseases.

Protein prenylation is a post-translational modification process in which a lipophilic group, such as a farnesyl or geranylgeranyl moiety, is covalently attached to specific cysteine residues near the carboxy-terminus of proteins. This modification plays a crucial role in membrane targeting and protein-protein interactions, particularly for proteins involved in signal transduction pathways, such as Ras family GTPases. The enzymes responsible for prenylation are called protein prenyltransferases, and their dysfunction has been implicated in various diseases, including cancer and neurodegenerative disorders.

Monounsaturated fatty acids (MUFAs) are a type of fatty acid that contains one double bond in its chemical structure. The presence of the double bond means that there is one less hydrogen atom, hence the term "unsaturated." In monounsaturated fats, the double bond occurs between the second and third carbon atoms in the chain, which makes them "mono"unsaturated.

MUFAs are considered to be a healthy type of fat because they can help reduce levels of harmful cholesterol (low-density lipoprotein or LDL) while maintaining levels of beneficial cholesterol (high-density lipoprotein or HDL). They have also been associated with a reduced risk of heart disease and improved insulin sensitivity.

Common sources of monounsaturated fats include olive oil, canola oil, avocados, nuts, and seeds. It is recommended to consume MUFAs as part of a balanced diet that includes a variety of nutrient-dense foods.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Dietary cholesterol is a type of cholesterol that comes from the foods we eat. It is present in animal-derived products such as meat, poultry, dairy products, and eggs. While dietary cholesterol can contribute to an increase in blood cholesterol levels for some people, it's important to note that saturated and trans fats have a more significant impact on blood cholesterol levels than dietary cholesterol itself.

The American Heart Association recommends limiting dietary cholesterol intake to less than 300 milligrams per day for most people, and less than 200 milligrams per day for those with a history of heart disease or high cholesterol levels. However, individual responses to dietary cholesterol can vary, so it's essential to monitor blood cholesterol levels and adjust dietary habits accordingly.

Tetrahydrofolate dehydrogenase (EC 1.5.1.20) is an enzyme involved in folate metabolism. The enzyme catalyzes the oxidation of tetrahydrofolate (THF) to dihydrofolate (DHF), while simultaneously reducing NADP+ to NADPH.

The reaction can be summarized as follows:

THF + NADP+ -> DHF + NADPH + H+

This enzyme plays a crucial role in the synthesis of purines and thymidylate, which are essential components of DNA and RNA. Therefore, any defects or deficiencies in tetrahydrofolate dehydrogenase can lead to various medical conditions, including megaloblastic anemia and neural tube defects during fetal development.

Cholesterol 7-alpha-hydroxylase (CYP7A1) is an enzyme that plays a crucial role in the regulation of cholesterol homeostasis in the body. It is located in the endoplasmic reticulum of hepatic cells and is responsible for the rate-limiting step in the synthesis of bile acids from cholesterol.

The enzyme catalyzes the conversion of cholesterol to 7α-hydroxycholesterol, which is then further metabolized to form primary bile acids, including cholic acid and chenodeoxycholic acid. These bile acids are essential for the digestion and absorption of fats and fat-soluble vitamins in the small intestine.

Additionally, CYP7A1 is also involved in the regulation of cholesterol levels in the body by providing negative feedback to the synthesis of cholesterol in the liver. When cholesterol levels are high, the activity of CYP7A1 increases, leading to an increase in bile acid synthesis and a decrease in cholesterol levels. Conversely, when cholesterol levels are low, the activity of CYP7A1 decreases, reducing bile acid synthesis and allowing cholesterol levels to rise.

Abnormalities in CYP7A1 function have been implicated in several diseases, including gallstones, liver disease, and cardiovascular disease.

Sitosterols are a type of plant sterol or phytosterol that are structurally similar to cholesterol, a steroid lipid found in animals. They are found in small amounts in human diets, primarily in vegetable oils, nuts, seeds, and avocados. Sitosterols are not synthesized by the human body but can be absorbed from the diet and have been shown to lower cholesterol levels in the blood when consumed in sufficient quantities. This is because sitosterols compete with cholesterol for absorption in the digestive tract, reducing the amount of cholesterol that enters the bloodstream. Some margarines and other foods are fortified with sitosterols or other phytosterols to help reduce cholesterol levels in people with high cholesterol.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Sterol Regulatory Element Binding Protein 2 (SREBP-2) is a transcription factor that plays a crucial role in the regulation of cholesterol homeostasis in the body. It is a member of the SREBP family, which also includes SREBP-1a and SREBP-1c, and is encoded by the SREBF2 gene.

SREBP-2 is primarily involved in the regulation of genes that are necessary for cholesterol synthesis and uptake. When cholesterol levels in the body are low, SREBP-2 gets activated and moves from the endoplasmic reticulum to the Golgi apparatus, where it undergoes proteolytic cleavage to release its active form. The active SREBP-2 then translocates to the nucleus and binds to sterol regulatory elements (SREs) in the promoter regions of target genes, thereby inducing their transcription.

The target genes of SREBP-2 include HMG-CoA reductase, which is a rate-limiting enzyme in cholesterol synthesis, and LDL receptor, which is responsible for the uptake of low-density lipoprotein (LDL) or "bad" cholesterol from the bloodstream. By upregulating the expression of these genes, SREBP-2 helps to increase cholesterol levels in the body and maintain cholesterol homeostasis.

Dysregulation of SREBP-2 has been implicated in various diseases, including atherosclerosis, cardiovascular disease, and cancer.

NADP (Nicotinamide Adenine Dinucleotide Phosphate) is a coenzyme that plays a crucial role as an electron carrier in various redox reactions in the human body. It exists in two forms: NADP+, which functions as an oxidizing agent and accepts electrons, and NADPH, which serves as a reducing agent and donates electrons.

NADPH is particularly important in anabolic processes, such as lipid and nucleotide synthesis, where it provides the necessary reducing equivalents to drive these reactions forward. It also plays a critical role in maintaining the cellular redox balance by participating in antioxidant defense mechanisms that neutralize harmful reactive oxygen species (ROS).

In addition, NADP is involved in various metabolic pathways, including the pentose phosphate pathway and the Calvin cycle in photosynthesis. Overall, NADP and its reduced form, NADPH, are essential molecules for maintaining proper cellular function and energy homeostasis.

Methionine sulfoxide reductases (MSRs) are a group of enzymes that catalyze the reduction of methionine sulfoxides back to methionine in proteins. Methionine residues in proteins can be oxidized by reactive oxygen species (ROS) or other oxidizing agents, leading to the formation of methionine sulfoxide. This modification can affect protein function and stability. MSRs play a crucial role in protecting proteins from oxidative damage and maintaining their proper function.

There are two types of MSRs, designated as MSRA and MSRB. MSRA reduces methionine-S-sulfoxides, while MSRB reduces methionine-R-sulfoxides. Both enzymes require the cofactor thioredoxin to reduce the methionine sulfoxide back to methionine. The activity of MSRs is important in various biological processes, including protein folding, stress response, and aging. Defects in MSRs have been implicated in several diseases, such as Alzheimer's disease, Parkinson's disease, and cancer.

Naphthalene is not typically referred to as a medical term, but it is a chemical compound with the formula C10H8. It is a white crystalline solid that is aromatic and volatile, and it is known for its distinctive mothball smell. In a medical context, naphthalene is primarily relevant as a potential toxin or irritant.

Naphthalene can be found in some chemical products, such as mothballs and toilet deodorant blocks. Exposure to high levels of naphthalene can cause symptoms such as nausea, vomiting, diarrhea, and headaches. Long-term exposure has been linked to anemia and damage to the liver and nervous system.

In addition, naphthalene is a known environmental pollutant that can be found in air, water, and soil. It is produced by the combustion of fossil fuels and is also released from some industrial processes. Naphthalene has been shown to have toxic effects on aquatic life and may pose a risk to human health if exposure levels are high enough.

Ribonucleoside Diphosphate Reductase (RNR) is an enzyme that plays a crucial role in the regulation of DNA synthesis and repair. It catalyzes the conversion of ribonucleoside diphosphates (NDPs) to deoxyribonucleoside diphosphates (dNDPs), which are the building blocks of DNA. This reaction is essential for the synthesis of new DNA strands during replication and repair processes. The enzyme's activity is tightly regulated, as it must be carefully controlled to prevent errors in DNA synthesis that could lead to mutations and genomic instability. RNR is a target for chemotherapeutic agents due to its essential role in DNA synthesis.

LDL receptors (Low-Density Lipoprotein Receptors) are cell surface receptors that play a crucial role in the regulation of cholesterol homeostasis within the body. They are responsible for recognizing and binding to LDL particles, also known as "bad cholesterol," which are then internalized by the cell through endocytosis.

Once inside the cell, the LDL particles are broken down, releasing their cholesterol content, which can be used for various cellular processes such as membrane synthesis and hormone production. The LDL receptors themselves are recycled back to the cell surface, allowing for continued uptake of LDL particles.

Mutations in the LDL receptor gene can lead to a condition called familial hypercholesterolemia, which is characterized by high levels of LDL cholesterol in the blood and an increased risk of premature cardiovascular disease.

Bile acids and salts are naturally occurring steroidal compounds that play a crucial role in the digestion and absorption of lipids (fats) in the body. They are produced in the liver from cholesterol and then conjugated with glycine or taurine to form bile acids, which are subsequently converted into bile salts by the addition of a sodium or potassium ion.

Bile acids and salts are stored in the gallbladder and released into the small intestine during digestion, where they help emulsify fats, allowing them to be broken down into smaller molecules that can be absorbed by the body. They also aid in the elimination of waste products from the liver and help regulate cholesterol metabolism.

Abnormalities in bile acid synthesis or transport can lead to various medical conditions, such as cholestatic liver diseases, gallstones, and diarrhea. Therefore, understanding the role of bile acids and salts in the body is essential for diagnosing and treating these disorders.

Oxidoreductases acting on CH-CH group donors are a class of enzymes within the larger group of oxidoreductases, which are responsible for catalyzing oxidation-reduction reactions. Specifically, this subclass of enzymes acts upon donors containing a carbon-carbon (CH-CH) bond, where one atom or group of atoms is oxidized and another is reduced during the reaction process. These enzymes play crucial roles in various metabolic pathways, including the breakdown and synthesis of carbohydrates, lipids, and amino acids.

The reactions catalyzed by these enzymes involve the transfer of electrons and hydrogen atoms between the donor and an acceptor molecule. This process often results in the formation or cleavage of carbon-carbon bonds, making them essential for numerous biological processes. The systematic name for this class of enzymes is typically structured as "donor:acceptor oxidoreductase," where donor and acceptor represent the molecules involved in the electron transfer process.

Examples of enzymes that fall under this category include:

1. Aldehyde dehydrogenases (EC 1.2.1.3): These enzymes catalyze the oxidation of aldehydes to carboxylic acids, using NAD+ as an electron acceptor.
2. Dihydrodiol dehydrogenase (EC 1.3.1.14): This enzyme is responsible for the oxidation of dihydrodiols to catechols in the biodegradation of aromatic compounds.
3. Succinate dehydrogenase (EC 1.3.5.1): A key enzyme in the citric acid cycle, succinate dehydrogenase catalyzes the oxidation of succinate to fumarate and reduces FAD to FADH2.
4. Xylose reductase (EC 1.1.1.307): This enzyme is involved in the metabolism of pentoses, where it reduces xylose to xylitol using NADPH as a cofactor.

Quinone reductases are a group of enzymes that catalyze the reduction of quinones to hydroquinones, using NADH or NADPH as an electron donor. This reaction is important in the detoxification of quinones, which are potentially toxic compounds produced during the metabolism of certain drugs, chemicals, and endogenous substances.

There are two main types of quinone reductases: NQO1 (NAD(P)H:quinone oxidoreductase 1) and NQO2 (NAD(P)H:quinone oxidoreductase 2). NQO1 is a cytosolic enzyme that can reduce a wide range of quinones, while NQO2 is a mitochondrial enzyme with a narrower substrate specificity.

Quinone reductases have been studied for their potential role in cancer prevention and treatment, as they may help to protect cells from oxidative stress and DNA damage caused by quinones and other toxic compounds. Additionally, some quinone reductase inhibitors have been developed as chemotherapeutic agents, as they can enhance the cytotoxicity of certain drugs that require quinone reduction for activation.

... a Hydroxymethylglutaryl-CoA reductase (EC 1.1.1.88) is an enzyme that catalyzes the chemical reaction (R)-mevalonate + CoA + 2 ... acylating CoA)". Biochemistry. 4 (10): 2086-2090. doi:10.1021/bi00886a025. Hydroxymethylglutaryl-CoA+reductase at the U.S. ... beta-hydroxy-beta-methylglutaryl CoA-reductase, 3-hydroxy-3-methylglutaryl coenzyme A reductase, and hydroxymethylglutaryl ... CoA, and NAD+, whereas its 3 products are 3-hydroxy-3-methylglutaryl-CoA, NADH, and H+. This enzyme belongs to the family of ...
... acetylating-CoA) 3-hydroxy-3-methylglutaryl CoA reductase (NADPH) hydroxymethylglutaryl-CoA reductase (NADPH2). As of late 2007 ... 3-hydroxy-3-methylglutaryl-CoA reductase β-hydroxy-β-methylglutaryl coenzyme A reductase hydroxymethylglutaryl CoA reductase ( ... NADPH) S-3-hydroxy-3-methylglutaryl-CoA reductase NADPH-hydroxymethylglutaryl-CoA reductase HMGCoA reductase-mevalonate:NADP- ... In enzymology, a hydroxymethylglutaryl-CoA reductase (NADPH) (EC 1.1.1.34) is an enzyme that catalyzes the chemical reaction (R ...
... hydroxymethylglutaryl-CoA reductase (NADPH)]-phosphatase (EC 3.1.3.47) catalyzes the reaction [hydroxymethylglutaryl-CoA ... hydroxymethylglutaryl-CoA reductase (NADPH)]-phosphate phosphohydrolase. This enzyme is also called reductase phosphatase. Gil ... reductase (NADPH)] phosphate + H2O ⇌ {\displaystyle \rightleftharpoons } [hydroxymethylglutaryl-CoA reductase (NADPH)] + ... Gil G, Sitges M, Hegardt FG (1981). "Purification and properties of rat liver hydroxymethylglutaryl coenzyme A reductase ...
In the major pathway, pravastatin inhibits the function of hydroxymethylglutaryl-CoA (HMG-CoA) reductase. As a reversible ... Like all statins, pravastatin works by inhibiting HMG-CoA reductase, an enzyme found in liver that plays a role in producing ... Tobert JA (July 2003). "Lovastatin and beyond: the history of the HMG-CoA reductase inhibitors". Nature Reviews. Drug Discovery ... pravastatin sterically hinders the action of HMG-CoA reductase by occupying the active site of the enzyme. Taking place ...
Statins act by inhibiting the enzyme hydroxymethylglutaryl CoA reductase (HMG-CoA-reductase) in the liver. In response, the ... Synthesis of cholesterol by the liver is suppressed in the HMG-CoA reductase pathway. In FH, LDL receptor function is reduced ... Initially, they found increased activity of HMG-CoA reductase, but studies showed that this did not explain the very abnormal ... identification of a defect in the regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity associated with ...
... hydroxymethylglutaryl-CoA reductase (NADPH)] kinase}]], whereas its two products are ADP and [[{[hydroxymethylglutaryl-CoA ... hydroxymethylglutaryl-CoA reductase (NADPH)] kinase} ⇌ {\displaystyle \rightleftharpoons } ADP + {[hydroxymethylglutaryl-CoA ... hydroxymethylglutaryl coenzyme A reductase kinase kinase, (phosphorylating), reductase kinase, reductase kinase kinase, and ... hydroxymethylglutaryl-CoA reductase (NADPH)] kinase} phosphotransferase. Other names in common use include AMP-activated kinase ...
... independent of hydroxymethyl glutaryl-CoA reductase". Proceedings of the National Academy of Sciences of the United States of ... Lovastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), an enzyme that catalyzes the ... HMG CoA reductase occurs early in the biosynthetic pathway and is among the first committed steps to cholesterol formulation. ... It works by decreasing the liver's ability to produce cholesterol by blocking the enzyme HMG-CoA reductase. Lovastatin was ...
Statins work by inhibiting HMG-CoA (hydroxymethylglutaryl-coenzyme A) reductase, a hepatic rate-limiting enzyme in ...
... human organic anion transporting polypeptide and identification of rat and human hydroxymethylglutaryl-CoA reductase inhibitor ...
Statins competitively inhibit hydroxymethylglutaryl (HMG) CoA reductase which is used in the biosynthesis of cholesterol and ... Istvan, Eva S.; Deisenhofer, Johann (2001-05-11). "Structural Mechanism for Statin Inhibition of HMG-CoA Reductase". Science. ...
There are two distinct classes of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase enzymes: class I consists of eukaryotic ... Class I HMG-CoA reductases catalyse the NADP-dependent synthesis of mevalonate from 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA). ... Class II HMG-CoA reductases catalyse the reverse reaction of class I enzymes, namely the NAD-dependent synthesis of HMG-CoA ... Class I HMG-CoA reductases consist of an N-terminal membrane domain (lacking in archaeal enzymes), and a C-terminal catalytic ...
... hydroxymethylglutaryl-coa reductase inhibitors MeSH D27.505.519.186.071.601 - lipotropic agents MeSH D27.505.519.186.144 - ... hydroxymethylglutaryl-coa reductase inhibitors MeSH D27.505.519.389.375 - integrase inhibitors MeSH D27.505.519.389.375.400 - ... hydroxymethylglutaryl-coa reductase inhibitors MeSH D27.505.954.230.601 - lipotropic agents MeSH D27.505.954.248 - ...
... and mononuclear leukocyte hydroxymethylglutaryl-coenzyme A reductase (HMG-CoA reductase), the rate-controlling enzyme in the ... recent data indicate that secondary effects of unknown regulators other than sitosterol can lead to reduced HMG-CoA reductase ...
... hydroxymethylglutaryl-CoA reductase (NADPH) EC 1.1.1.35: 3-hydroxyacyl-CoA dehydrogenase EC 1.1.1.36: acetoacetyl-CoA reductase ... cis-2-enoyl-CoA reductase (NADPH) EC 1.3.1.38: trans-2-enoyl-CoA reductase (NADPH) EC 1.3.1.39: trans-2-enoyl-CoA reductase ( ... reductase EC 1.3.1.93: very-long-chain enoyl-CoA reductase EC 1.3.1.94: polyprenol reductase EC 1.3.1.95: acrylyl-CoA reductase ... acrylyl-CoA reductase (NADPH) EC 1.3.1.85: crotonyl-CoA carboxylase/reductase EC 1.3.1.86: crotonyl-CoA reductase EC 1.3.1.87: ...
Hydroxymethylglutaryl-coenzyme A reductase inhibitors (HMG-CoA inhibitors or statins) Statins may sometimes cause myalgia and ...
The discovery of HMG-CoA (3-hydroxy-3-methylglutaryl-CoA) reductase inhibitors, called statins, was a breakthrough in the ... Moghadasian, Mohammed H. (May 1999). "Clinical pharmacology of 3-hydroxy-methylglutaryl coenzyme A reductase inhibitors". Life ... Hence HMG-CoA reductase (HMGR) became a natural target. HMGR was found to be the rate-limiting enzyme in the cholesterol ... Tobert, Jonathan A. (July 2003). "Lovastatin and beyond: The history of the HMG-CoA reductase inhibitors". Nature Reviews Drug ...
... hydroxymethylglutaryl-CoA reductase (NADPH)]-phosphatase EC 3.1.3.48: protein-tyrosine-phosphatase EC 3.1.3.49: [pyruvate ... succinyl-CoA hydrolase EC 3.1.2.4: 3-hydroxyisobutyryl-CoA hydrolase EC 3.1.2.5: hydroxymethylglutaryl-CoA hydrolase EC 3.1.2.6 ... EC 3.1.2.25: phenylacetyl-CoA hydrolase EC 3.1.2.26: Now EC 2.8.3.25, bile acid CoA transferase EC 3.1.2.27: choloyl-CoA ... ADP-dependent short-chain-acyl-CoA hydrolase EC 3.1.2.19: ADP-dependent medium-chain-acyl-CoA hydrolase EC 3.1.2.20: acyl-CoA ...
... hydroxymethylglutaryl coa reductases MeSH D08.811.682.047.385.415.250 - hydroxymethylglutaryl-coa reductases, nad-dependent ... hydroxymethylglutaryl-coa-reductases, nadp-dependent MeSH D08.811.682.047.393 - hydroxybutyrate dehydrogenase MeSH D08.811. ... reductase (nadph, b-specific) MeSH D08.811.682.660.425 - Glutaryl-CoA dehydrogenase MeSH D08.811.682.660.462 - isovaleryl-coa ... acyl-coa dehydrogenase, long-chain MeSH D08.811.682.660.150.200 - acyl-CoA oxidase MeSH D08.811.682.660.150.300 - butyryl-coa ...
An hydroxymethylglutaryl-CoA synthase cassette (mevalonate pathway) catlyzes the formation of hydroxymethylglutaryl acid by the ... The CurB (ACP), CurC (ketosynthase), and CurD (HMG-CoA reductase) are responsible for the formation of (S)HMG-ACP3. HaI, from ... Analysis of the pathway demonstrated the presence of one NRPS/PKS hybrid module located on CurF, one HMG-CoA synthase cassette ... addition of an malonyl-CoA unit to the terminal ketide of the aceto-acetyl-ACP moiety of ACP1,ACP2, or ACP3. subsequent enzymes ...
... of the newborn Hepatic congestion Hepatic failure Hereditary ACTH resistance HMG-CoA lyase deficiency Hydroxymethylglutaryl-CoA ... Chlorpropamide Cibenzoline Cirrhosis Cleft lip palate pituitary deficiency Clove Coenzyme Q cytochrome c reductase deficiency ... 2-methylbutyryl-coenzyme A dehydrogenase deficiency 3-alpha-hydroxyacyl-CoA dehydrogenase deficiency 3-Methylcrotonyl-CoA ... Maldigestion Malonyl-CoA decarboxylase deficiency Maple syrup urine disease Mcquarrie type infantile idiopathic hypoglycemia ...
"On the Inhibitor Effects of Bergamot Juice Flavonoids Binding to the 3-Hydroxy-3-methylglutaryl-CoA Reductase (HMGR) Enzyme". J ... Isolation of 3-Hydroxymethylglutaryl Flavonoid Glycosides". Journal of Natural Products. 72 (7): 1352-1354. doi:10.1021/ ...
"On the Inhibitor Effects of Bergamot Juice Flavonoids Binding to the 3-Hydroxy-3-methylglutaryl-CoA Reductase (HMGR) Enzyme". J ... Isolation of 3-Hydroxymethylglutaryl Flavonoid Glycosides". Journal of Natural Products. 72 (7): 1352-1354. doi:10.1021/ ...
... chain L-3-hydroxy acyl-CoA dehydrogenase deficiency Medium-chain ketoacyl-CoA thiolase deficiency Dienoyl-CoA reductase ... 1 in 75,000 Hydroxymethylglutaryl lyase deficiency (HMG) < 1 in 100,000 Isovaleric acidemia (IVA) < 1 in 100,000 3- ... butyric aciduria Isobutyryl-CoA dehydrogenase deficiency 2-Methylbutyryl-CoA dehydrogenase deficiency 3-Methylglutaconyl-CoA ... Methylcrotonyl-CoA carboxylase deficiency (3MCC) > 1 in 75,000 Methylmalonyl-CoA mutase deficiency (MUT) > 1 in 75,000 ...
... hydroxymethylglutaryl-CoA reductase (NADPH)] kinase EC 2.7.1.110: Now EC 2.7.11.3, dephospho-(reductase kinase) kinase EC 2.7. ... cinnamoyl-CoA:phenyllactate CoA-transferase EC 2.8.3.18: succinyl-CoA:acetate CoA-transferase (*) EC 2.8.3.19: CoA:oxalate CoA- ... succinyl-CoA-L-malate CoA-transferase and EC 2.8.3.20, succinyl-CoA-Dcitramalate CoA-transferase EC 2.8.3.8: acetate CoA- ... L-carnitine CoA-transferase (*) EC 2.8.3.22: succinyl-CoA-L-malate CoA-transferase (*) EC 2.8.3.23: caffeate CoA-transferase ...
... a Hydroxymethylglutaryl-CoA reductase (EC 1.1.1.88) is an enzyme that catalyzes the chemical reaction (R)-mevalonate + CoA + 2 ... acylating CoA)". Biochemistry. 4 (10): 2086-2090. doi:10.1021/bi00886a025. Hydroxymethylglutaryl-CoA+reductase at the U.S. ... beta-hydroxy-beta-methylglutaryl CoA-reductase, 3-hydroxy-3-methylglutaryl coenzyme A reductase, and hydroxymethylglutaryl ... CoA, and NAD+, whereas its 3 products are 3-hydroxy-3-methylglutaryl-CoA, NADH, and H+. This enzyme belongs to the family of ...
HMG-CoA) reductase and thereby reducing cholesterol synthesis. In X-ray crystallographic studies, we have determined the ... Hydroxymethylglutaryl CoA Reductases / metabolism * Hydroxymethylglutaryl-CoA Reductase Inhibitors / therapeutic use* * Liver ... Statin inhibition of HMG-CoA reductase: a 3-dimensional view Atheroscler Suppl. 2003 Mar;4(1):3-8. doi: 10.1016/s1567-5688(03) ... Statins act by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and thereby reducing cholesterol synthesis ...
ClinicalTrials.gov: Hydroxymethylglutaryl-CoA Reductase Inhibitors (National Institutes of Health) * ClinicalTrials.gov: ... Article: Effect and mechanism of HMG-CoA reductase inhibitor on the improvement of... ...
Hydroxymethylglutaryl-CoA Reductase Inhibitors / adverse effects* * Hydroxymethylglutaryl-CoA Reductase Inhibitors / ...
HMGCoA-reductase. hydroxymethylglutaryl-CoA-reductase (EC 1.1.1.34). HPLC. high-performance liquid chromatography. LDH. lactate ... These results suggest an indirect modulation of hydroxymethylglutaryl-CoA-reductase activity as the most likely inhibitory ... the inhibiting effect of artichoke extracts indicating an inhibition at the level of hydroxymethylglutaryl-CoA-reductase. ... In addition, the stimulation of HMGCoA-reductase activity by insulin was efficiently blocked by the extracts, although other ...
JID: 7902782; 0 (Anti-Inflammatory Agents, Non-Steroidal); 0 (Hydroxymethylglutaryl-CoA Reductase Inhibitors); R16CO5Y76E ( ...
Geelen, M. H., Gibson, D. & Rodwell, V. Hydroxymethylglutaryl-CoA reductase-the rate-limiting enzyme of cholesterol ... Grundy, S. M. HMG-CoA reductase inhibitors for treatment of hypercholesterolemia. N. Engl. J. Med. 319, 24-33 (1988). ... Highly sensitive assay of HMG-CoA reductase activity by LC-ESI-MS/MS. J. Lipid Res. 48, 1212-1220 (2007). ... Thyroid-stimulating hormone decreases HMG-CoA reductase phosphorylation via AMP-activated protein kinase in the liver. J. Lipid ...
Unexpectedly, HMGCR (3-hydroxy-3-methylglutaryl-CoA reductase) and G6PD (glucose-6-phosphate dehydrogenase), the rate-limiting ... and C19-steroids upon hepatic sterol synthesis and hydroxymethylglutaryl-CoA reductase activity. Arch Biochem Biophys. 1970;140 ... Unexpectedly, HMGCR (3-hydroxy-3-methylglutaryl-CoA reductase) and G6PD (glucose-6-phosphate dehydrogenase), the rate-limiting ... 3-hydroxy-3-methylglutaryl-CoA reductase) and G6DP (glucose-6-phosphate dehydrogenase), the rate-limiting enzymes of ...
5. Hepatic cholesterol synthesis and hydroxymethylglutaryl CoA reductase activity after injection of methylazoxymethanol ...
There are two distinct classes of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase enzymes: class I consists of eukaryotic ... Class I HMG-CoA reductases catalyse the NADP-dependent synthesis of mevalonate from 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA). ... Class II HMG-CoA reductases catalyse the reverse reaction of class I enzymes, namely the NAD-dependent synthesis of HMG-CoA ... In archaea, HMG-CoA reductase is a cytoplasmic enzyme involved in the biosynthesis of the isoprenoids side chains of lipids [ ( ...
... acetylating-CoA); 3-hydroxy-3-methylglutaryl CoA reductase (NADPH); hydroxymethylglutaryl-CoA reductase (NADPH2). ... hydroxymethylglutaryl-CoA reductase (NADPH)] kinase} and reactivated by EC 3.1.3.47 {[hydroxymethylglutaryl-CoA reductase ( ... hydroxymethylglutaryl-CoA reductase (NADPH). Reaction:. (R)-mevalonate + CoA + 2 NADP+ = (S)-3-hydroxy-3-methylglutaryl-CoA + 2 ... S-3-hydroxy-3-methylglutaryl-CoA reductase (ambiguous); NADPH-hydroxymethylglutaryl-CoA reductase; HMGCoA reductase-mevalonate: ...
... coenzyme A reductase or HMG-CoA (statins are also called HMG-CoA inhibitors). HMG-CoA is one step in the process the liver ... Statins like Mevacor and Zocor bind with a cholesterol precursor chemical called hydroxymethylglutaryl- ...
... a moderate dose of a hydroxymethylglutaryl coenzyme A (HMG CoA) reductase inhibitor may be appropriate if the amount of ... HMG-CoA reductase inhibitors (statins). For patients with mixed hyperlipidemias (elevations of both LDL cholesterol and ...
... human organic anion transporting polypeptide and identification of rat and human hydroxymethylglutaryl-CoA reductase inhibitor ... Williams D and Feely J (2002) Pharmacokinetic-pharmacodynamic drug interactions with HMG-CoA reductase inhibitors. Clin ... In the last few years, statins, HMG-coenzyme A reductase inhibitors, became an important class of drugs, widely used in clinics ...
This explains why bacterial fermentation and inhibition of hydroxymethylglutaryl-CoA reductase, a protein that regulates ...
Rhabdomyolysis with HMG-CoA reductase inhibitors and gemfibrozil combination therapy. Pharmacoepidemiology and Drug Safety, ... One of the most common medicines used for correcting serum lipid profile are hydroxymethyl glutaryl coenzyme A (HMG-CoA) ... reductase inhibitors, or statins. They are used as primary prevention of cardiovascular diseases in high-risk people and ...
By inhibiting the 3-hydroxy-methylglutaryl coenzyme A (HMG-CoA) reductase, statins block the conversion of 3-hydroxy- ... U. Laufs, V. La Fata, J. Plutzky, and J. K. Liao, "Upregulation of endothelial nitric oxide synthase by HMG CoA reductase ... GPx oxidizes GSH to form glutathione disulfide (GSSG), a reaction that is reversed by the glutathione reductase, a NADPH- ... The thioredoxin (TRX) system, integrated by thioredoxin, NADPH, and thioredoxin reductase, regulates the equilibrium between ...
... in Agrobacterium tumefaciens by the additional use of a truncated version of the enzyme hydroxymethylglutaryl CoA reductase ( ... Y. lipolytica possesses a high concentration of acetyl-CoA, which is essential to enhance the production of β-carotene (Gao et ...
HMGR Hydroxymethylglutaryl-CoA reductase, ISPG (E)-4-hydroxy-3-methylbut-2-enyl-diphosphate synthase, ISPH 4-hydroxy-3- ... including hydroxymethylglutaryl-CoA reductase (HMGR), (E)-4-hydroxy-3-methylbut-2-enyl-diphosphate synthase (ISPG), 4-hydroxy-3 ... AACT Acetyl-CoA C-acetyltransferase, HMGS Hydroxymethylglutaryl-CoA synthase, ISPE 4-diphosphocytidyl-2-C-methyl-D-erythritol ... acetyl-CoA C-acetyltransferase (AACT) and hydroxymethylglutaryl-CoA synthase (HMGS). There was only 1 enzyme involved in ...
Important in mediating the effect of LDL (low density lipoprotein) uptake on suppression of hydroxymethylglutaryl-CoA reductase ... acyl-CoA) to form lysophosphatidic acid, which is then acylated with another molecule of acyl-CoA to yield phosphatidic acid. ... Has acyl-CoA ligase activity for long-chain and very-long-chain fatty acids. Gene Name:. SLC27A1. Uniprot ID:. Q6PCB7 Molecular ... Hepatic lipase has the capacity to catalyze hydrolysis of phospholipids, mono-, di-, and triglycerides, and acyl-CoA thioesters ...
Important in mediating the effect of LDL (low density lipoprotein) uptake on suppression of hydroxymethylglutaryl-CoA reductase ... Has acyl-CoA ligase activity for long-chain and very-long-chain fatty acids. Gene Name:. SLC27A1. Uniprot ID:. Q6PCB7 Molecular ... Hepatic lipase has the capacity to catalyze hydrolysis of phospholipids, mono-, di-, and triglycerides, and acyl-CoA thioesters ...
HMG-COA REDUCTASE INHIBITOR [EPC], HYDROXYMETHYLGLUTARYL-COA REDUCTASE INHIBITORS [MOA] These are the reported pharmaceutical ...
HMG-COA REDUCTASE INHIBITOR [EPC], HYDROXYMETHYLGLUTARYL-COA REDUCTASE INHIBITORS [MOA] These are the reported pharmaceutical ... LIPITOR (atorvastatin) is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. Atorvastatin calcium is [R ...
Keywords: Myocardial Infarction, Coronary Artery Disease, Lovastatin, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Heptanoic ...
HMG-CoA Reductase Inhibitor HMG-CoA Reductase Inhibitors Hydroxymethylglutaryl-CoA Reductase Inhibitor Inhibitors, HMG-CoA ... 98; see HMG-COA REDUCTASE INHIBITORS 1997; for HYDROXYMETHYLGLUTARYL-COA REDUCTASE INHIBITORS see HMG-COA REDUCTASE INHIBITORS ... Hydroxymethylglutaryl CoA Reductases/antagonists & inhibitors (1976-1996). See Also. Hydroxymethylglutaryl CoA Reductases. ... Reductase Inhibitors, Hydroxymethylglutaryl-CoA Inhibitors, Hydroxymethylglutaryl-Coenzyme A Statin Statins Statins, HMG-CoA ...
Hydroxymethylglutaryl-CoA Reductase Inhibitors. *Humans. *Cardiovascular System & Hematology. *Atherosclerosis. *1102 ...
Hydroxymethylglutaryl-CoA Reductase Inhibitors, Hypercholesterolemia, Hyperglycemia, Hypertension, Inflammation, Kidney Failure ...
Although all cell lines express mRNA encoding for hydroxymethylglutaryl-CoA reductase (HMGCR), the mitochondrial translocator ... Members of the short-chain dehydrogenase/reductase (SDR) and aldo-keto reductase (AKR) superfamilies mediate the reduction of ... aldo-keto reductases (AKR1A1, AKR1B1, AKR1C1, AKR1C2, AKR1C3, and AKR7A2) and carbonyl reductases (CBR1, CBR3), in human ... AKR1C3; aldo-keto reductase family 1 member C3. Aliases: DD3, DDX, PGFS, HAKRB, HAKRe, HA1753, HSD17B5, hluPGFS Location:. ...
  • How Do HMG-CoA Reductase Inhibitors Work? (rxlist.com)
  • Statins like Mevacor and Zocor bind with a cholesterol precursor chemical called hydroxymethylglutaryl- coenzyme A reductase or HMG-CoA (statins are also called HMG-CoA inhibitors). (rxlist.com)
  • In the last few years, statins, HMG-coenzyme A reductase inhibitors, became an important class of drugs, widely used in clinics to treat dyslipidemia. (aspetjournals.org)
  • RESULTS: Based on the estimated prevalence of lipid-lowering drug use in the Netherlands in 1998 (n = 520 800), we expected 60 cases of idiopathic myopathy due to hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) or fibric acid derivatives (fibrates). (uu.nl)
  • Other names in common use include beta-hydroxy-beta-methylglutaryl coenzyme A reductase, beta-hydroxy-beta-methylglutaryl CoA-reductase, 3-hydroxy-3-methylglutaryl coenzyme A reductase, and hydroxymethylglutaryl coenzyme A reductase. (wikipedia.org)
  • Statins act by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and thereby reducing cholesterol synthesis. (nih.gov)
  • Bucher, N.L.R., Overath, P. and Lynen, F. β-Hydroxy-β-methylglutaryl coenzyme A reductase, cleavage and condensing enzymes in relation to cholesterol formation in rat liver. (enzyme-database.org)
  • Kawachi, T. and Rudney, H. Solubilization and purification of β-hydroxy-β-methylglutaryl coenzyme A reductase from rat liver. (enzyme-database.org)
  • Glycerol-3-phosphate is first acylated with acyl-coenzyme A (acyl-CoA) to form lysophosphatidic acid, which is then acylated with another molecule of acyl-CoA to yield phosphatidic acid. (hmdb.ca)
  • LIPITOR (atorvastatin) is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. (hipaaspace.com)
  • It has been shown that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibition blocks hypertrophy, and we report here that "statin" therapy effectively suppresses small G protein activation and blunts hypertrophic growth in vitro and in vivo. (tamu.edu)
  • In Archaeal lipids its role is Hydroxymethylglutaryl-CoA reductase (EC 1.1.1.34) . (theseed.org)
  • Differences in statin structure and binding characteristics may partially contribute to differences in potency of HMG-CoA reductase inhibition and other pharmacologic properties. (nih.gov)
  • Replacement of 14 C-acetate by 14 C-mevalonate largely omitted the inhibiting effect of artichoke extracts indicating an inhibition at the level of hydroxymethylglutaryl-CoA-reductase. (aspetjournals.org)
  • The reduction of HMG-CoA to mevalonate is regulated by feedback inhibition by sterols and non-sterol metabolites derived from mevalonate, including cholesterol. (embl.de)
  • The treatment with artichoke led to the inhibition of the liver hydroxymethylglutaryl-CoA (HMG-CoA) reductase. (bvsalud.org)
  • Unexpectedly, HMGCR (3-hydroxy-3-methylglutaryl-CoA reductase) and G6PD (glucose-6-phosphate dehydrogenase), the rate-limiting enzymes of cholesterol synthesis and the PPP, were identified as direct targets of microRNA-206. (nature.com)
  • It also regulates cholesterol synthesis via phosphorylation and inactivation of hormone-sensitive lipase and hydroxymethylglutaryl-CoA reductase. (arigobio.cn)
  • regulates fatty acid and cholesterol synthesis by phosphorylating acetyl-CoA carboxylase (ACACA and ACACB) and hormone-sensitive lipase (LIPE) enzymes, respectively. (arigobio.cn)
  • In vertebrates, membrane-bound HMG-CoA reductase is the rate-limiting enzyme in the biosynthesis of cholesterol and other isoprenoids. (embl.de)
  • In enzymology, a Hydroxymethylglutaryl-CoA reductase (EC 1.1.1.88) is an enzyme that catalyzes the chemical reaction (R)-mevalonate + CoA + 2 NAD+ ⇌ {\displaystyle \rightleftharpoons } 3-hydroxy-3-methylglutaryl-CoA + 2 NADH + 2 H+ The 3 substrates of this enzyme are (R)-mevalonate, CoA, and NAD+, whereas its 3 products are 3-hydroxy-3-methylglutaryl-CoA, NADH, and H+. (wikipedia.org)
  • The systematic name of this enzyme class is (R)-mevalonate:NAD+ oxidoreductase (CoA-acylating). (wikipedia.org)
  • Class I HMG-CoA reductases catalyse the NADP-dependent synthesis of mevalonate from 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA). (embl.de)
  • HMG-CoA is one step in the process the liver cells use to manufacture cholesterol from simpler molecules. (rxlist.com)
  • Class I HMG-CoA reductases consist of an N-terminal membrane domain (lacking in archaeal enzymes), and a C-terminal catalytic region. (embl.de)
  • Une recherche documentaire a été effectuée dans PubMed de 1980 à 2021 en utilisant diverses combinaisons de termes MeSH comme tabac, diabète, hypertension, dyslipidémie, trouble dépressif majeur, trouble bipolaire, schizophrénie. (bvsalud.org)
  • This gene encodes a member of the aldo/keto reductase superfamily, which consists of more than 40 known enzymes and proteins. (cancerindex.org)
  • These results suggest an indirect modulation of hydroxymethylglutaryl-CoA-reductase activity as the most likely inhibitory mechanism of the artichoke extracts. (aspetjournals.org)
  • In addition, the stimulation of HMGCoA-reductase activity by insulin was efficiently blocked by the extracts, although other insulin-dependent phenomena, such as increased lactate production, were not influenced. (aspetjournals.org)
  • the E-value for the HMG-CoA_red domain shown below is 8.8e-76. (embl.de)
  • HMG-CoA_red, HMG-CoA reductase domain. (cdc.gov)
  • The statin drugs ('statins') potently inhibit hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase by competitively blocking the active site of the enzyme. (nih.gov)
  • Statins are synthetic drugs developed by pharmaceutical companies that block HMG-CoA reductase thereby lowering the level of cholesterol in the blood. (scientificpsychic.com)
  • 1. In the present study, we tested the hypothesis that long-term administration of the hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor simvastatin may regress hypertrophy and the possible effect of simvastatin on angiotensin-converting enzyme (ACE) activity in rats with pressure-overload cardiac hypertrophy. (nih.gov)
  • Hyperlipidemia: Familial hypercholesterolemia is managed with a hydroxymethylglutaryl coenzyme A (HMG CoA) reductase inhibitor, which is the mainstay of therapy and may be used in combination with other agents. (medscape.com)
  • Both medications selectively inhibit hydroxymethylglutaryl-coenzyme A reductase (HMG-CoA reductase), thereby decreasing bile cholesterol supersaturation and lithogenicity. (medscape.com)
  • Compounds that inhibit HYDROXYMETHYLGLUTARYL COA REDUCTASES . (bvsalud.org)
  • The enzyme hydroxy-methylglutaryl-coenzyme A reductase (HMG-CoA reductase or HMGR) is responsible for making cholesterol in the liver. (scientificpsychic.com)
  • This causes an increased demand for cholesterol in the liver cells, resulting in the dual effect of increasing transcription and activity of the cholesterol biosynthetic enzyme, HMG-CoA reductase, and increasing the number of hepatic LDL receptors. (clustermed.info)
  • In enzymology, a Hydroxymethylglutaryl-CoA reductase (EC 1.1.1.88) is an enzyme that catalyzes the chemical reaction (R)-mevalonate + CoA + 2 NAD+ ⇌ {\displaystyle \rightleftharpoons } 3-hydroxy-3-methylglutaryl-CoA + 2 NADH + 2 H+ The 3 substrates of this enzyme are (R)-mevalonate, CoA, and NAD+, whereas its 3 products are 3-hydroxy-3-methylglutaryl-CoA, NADH, and H+. (wikipedia.org)
  • The systematic name of this enzyme class is (R)-mevalonate:NAD+ oxidoreductase (CoA-acylating). (wikipedia.org)