Page last updated: 2024-10-24
cholesterol ester hydrolysis involved in cholesterol transport
Definition
Target type: biologicalprocess
The cholesterol metabolic process in which cholesterol esters are hydrolyzed into free fatty acids and cholesterol in the lysosome that contributes to intracellular cholesterol transport. [GOC:ascb_2009, GOC:dph, GOC:tb]
Cholesterol ester hydrolysis is a crucial step in cholesterol transport, particularly in the process of reverse cholesterol transport (RCT). This process involves the breakdown of cholesterol esters, which are hydrophobic molecules formed by the esterification of cholesterol with a fatty acid. Here's a detailed breakdown:
**1. Formation of Cholesterol Esters:**
* Cholesterol, obtained from dietary sources or synthesized by the liver, is esterified with fatty acids by the enzyme acyl-CoA:cholesterol acyltransferase (ACAT) in various tissues, including the small intestine, liver, and adrenal glands. This conversion forms cholesterol esters, which are more hydrophobic and can be readily incorporated into lipoproteins.
**2. Packaging into Lipoproteins:**
* Cholesterol esters are packaged within lipoproteins, primarily high-density lipoproteins (HDL), for transport through the bloodstream.
**3. Delivery to the Liver:**
* HDL particles, carrying cholesterol esters, circulate in the bloodstream and deliver them to the liver. This is the key step in reverse cholesterol transport, where cholesterol is removed from peripheral tissues and transported back to the liver for excretion.
**4. Hydrolysis by Cholesterol Esterase:**
* Upon reaching the liver, HDL particles interact with the enzyme cholesterol esterase (CE), also known as lecithin-cholesterol acyltransferase (LCAT). CE catalyzes the hydrolysis of cholesterol esters, breaking them down into free cholesterol and a fatty acid. This reaction is critical for releasing cholesterol from the HDL particles.
**5. Uptake by the Liver:**
* The free cholesterol released by CE hydrolysis is readily taken up by the liver cells, where it can be further metabolized or excreted.
**Key Players in Cholesterol Ester Hydrolysis:**
* **Acyl-CoA:cholesterol acyltransferase (ACAT):** Synthesizes cholesterol esters for packaging into lipoproteins.
* **Lecithin-cholesterol acyltransferase (LCAT):** Hydrolyzes cholesterol esters, releasing free cholesterol for liver uptake.
**Overall, cholesterol ester hydrolysis plays a critical role in cholesterol transport, particularly in the process of reverse cholesterol transport. By breaking down cholesterol esters and releasing free cholesterol, this process enables the efficient removal of cholesterol from peripheral tissues and its delivery to the liver for excretion.**'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| Liver carboxylesterase 1 | A liver carboxylesterase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P23141] | Homo sapiens (human) |
Compounds (84)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| bis(4-nitrophenyl)phosphate | bis(4-nitrophenyl)phosphate: RN given refers to parent cpd | aryl phosphate | |
| 4-methylumbelliferyl acetate | 4-methylumbelliferyl acetate : An acetate ester consiting of umbelliferone carrying a 7-O-acetyl group. | acetate ester; coumarins | plant metabolite |
| diacetyl | butane-2,3-dione : An alpha-diketone that is butane substituted by oxo groups at positions 2 and 3. It is a metabolite produced during the malolactic fermentation. | alpha-diketone | Escherichia coli metabolite; Saccharomyces cerevisiae metabolite |
| 6,7-dichloroquinoxaline-2,3-dione | quinoxaline derivative | ||
| tacrine | tacrine : A member of the class of acridines that is 1,2,3,4-tetrahydroacridine substituted by an amino group at position 9. It is used in the treatment of Alzheimer's disease. Tacrine: A cholinesterase inhibitor that crosses the blood-brain barrier. Tacrine has been used to counter the effects of muscle relaxants, as a respiratory stimulant, and in the treatment of Alzheimer's disease and other central nervous system disorders. | acridines; aromatic amine | EC 3.1.1.7 (acetylcholinesterase) inhibitor |
| ethacridine | Ethacridine: A topically applied anti-infective agent. | acridines | |
| aniracetam | N-acylpyrrolidine; pyrrolidin-2-ones | ||
| camostat | camostat : A benzoate ester resulting from the formal condensation of the carboxy group of 4-guanidinobenzoic acid with the hydroxy group of 2-(dimethylamino)-2-oxoethyl (4-hydroxyphenyl)acetate. It is a potent inhibitor of the human transmembrane protease serine 2 (TMPRSS2) and its mesylate salt is currently under investigation for its effectiveness in COVID-19 patients. | benzoate ester; carboxylic ester; diester; guanidines; tertiary carboxamide | anti-inflammatory agent; anticoronaviral agent; antifibrinolytic drug; antihypertensive agent; antineoplastic agent; antiviral agent; serine protease inhibitor |
| dilazep | dilazep : A member of the class of diazepanes that is 1,4-diazepane substituted by 3-[(3,4,5-trimethoxybenzoyl)oxy]propyl groups at positions 1 and 4. It is a potent adenosine uptake inhibitor that exhibits antiplatelet, antianginal and vasodilator properties. Dilazep: Coronary vasodilator with some antiarrhythmic activity. | benzoate ester; diazepane; diester; methoxybenzenes | cardioprotective agent; platelet aggregation inhibitor; vasodilator agent |
| benzophenone | benzophenone : The simplest member of the class of benzophenones, being formaldehyde in which both hydrogens are replaced by phenyl groups. | benzophenones | photosensitizing agent; plant metabolite |
| valproic acid | valproic acid : A branched-chain saturated fatty acid that comprises of a propyl substituent on a pentanoic acid stem. Valproic Acid: A fatty acid with anticonvulsant and anti-manic properties that is used in the treatment of EPILEPSY and BIPOLAR DISORDER. The mechanisms of its therapeutic actions are not well understood. It may act by increasing GAMMA-AMINOBUTYRIC ACID levels in the brain or by altering the properties of VOLTAGE-GATED SODIUM CHANNELS. | branched-chain fatty acid; branched-chain saturated fatty acid | anticonvulsant; antimanic drug; EC 3.5.1.98 (histone deacetylase) inhibitor; GABA agent; neuroprotective agent; psychotropic drug; teratogenic agent |
| donepezil | 2-[(1-benzylpiperidin-4-yl)methyl]-5,6-dimethoxyindan-1-one : A member of the class of indanones that is 5,6-dimethoxyindan-1-one which is substituted at position 2 by an (N-benzylpiperidin-4-yl)methyl group. donepezil : A racemate comprising equimolar amounts of (R)- and (S)-donepezil. A centrally acting reversible acetylcholinesterase inhibitor, its main therapeutic use is in the treatment of Alzheimer's disease where it is used to increase cortical acetylcholine. Donepezil: An indan and piperidine derivative that acts as a selective and reversible inhibitor of ACETYLCHOLINESTERASE. Donepezil is highly selective for the central nervous system and is used in the management of mild to moderate DEMENTIA in ALZHEIMER DISEASE. | aromatic ether; indanones; piperidines; racemate | EC 3.1.1.7 (acetylcholinesterase) inhibitor; EC 3.1.1.8 (cholinesterase) inhibitor; nootropic agent |
| beta-lapachone | beta-lapachone : A benzochromenone that is 3,4-dihydro-2H-benzo[h]chromene-5,6-dione substituted by geminal methyl groups at position 2. Isolated from Tabebuia avellanedae, it exhibits antineoplastic and anti-inflammatory activities. beta-lapachone: antineoplastic inhibitor of reverse transcriptase, DNA topoisomerase, and DNA polymerase | benzochromenone; orthoquinones | anti-inflammatory agent; antineoplastic agent; plant metabolite |
| meperidine | Meperidine: A narcotic analgesic that can be used for the relief of most types of moderate to severe pain, including postoperative pain and the pain of labor. Prolonged use may lead to dependence of the morphine type; withdrawal symptoms appear more rapidly than with morphine and are of shorter duration. pethidine : A piperidinecarboxylate ester that is piperidine which is substituted by a methyl group at position 1 and by phenyl and ethoxycarbonyl groups at position 4. It is an analgesic which is used for the treatment of moderate to severe pain, including postoperative pain and labour pain. | ethyl ester; piperidinecarboxylate ester; tertiary amino compound | antispasmodic drug; kappa-opioid receptor agonist; mu-opioid receptor agonist; opioid analgesic |
| quinone | 1,4-benzoquinone : The simplest member of the class of 1,4-benzoquinones, obtained by the formal oxidation of hydroquinone to the corresponding diketone. It is a metabolite of benzene. benzoquinone : The simplest members of the class of benzoquinones, consisting of cyclohexadiene which is substituted by two oxo groups. quinone : Compounds having a fully conjugated cyclic dione structure, such as that of benzoquinones, derived from aromatic compounds by conversion of an even number of -CH= groups into -C(=O)- groups with any necessary rearrangement of double bonds (polycyclic and heterocyclic analogues are included). | 1,4-benzoquinones | cofactor; human xenobiotic metabolite; mouse metabolite |
| acenaphthenequinone | acenaphthoquinone : An orthoquinone that is the 1,2-dioxo derivative of acenaphthene. | orthoquinones | chain carrier; epitope |
| 9,10-phenanthrenequinone | 9,10-phenanthrenequinone: structure | phenanthrenes | |
| 5-bromoisatin | indoles | anticoronaviral agent | |
| isatin | tribulin: endogenous MONOAMINE OXIDASE inhibitory activity extractable into ethyl acetate found in brain and many mammalian tissues and fluids; ISATIN is a major component; produced in excess following alcohol withdrawal; | indoledione | EC 1.4.3.4 (monoamine oxidase) inhibitor; plant metabolite |
| chloranil | Chloranil: A quinone fungicide used for treatment of seeds and foliage. tetrachloro-1,4-benzoquinone : A member of the class of 1,4-benzoquiones that is 1,4-benzoquinone in which all four hydrogens are substituted by chlorines. | 1,4-benzoquinones; organochlorine compound | EC 2.7.1.33 (pantothenate kinase) inhibitor; metabolite |
| benzoin | benzoins; secondary alpha-hydroxy ketone | EC 3.1.1.1 (carboxylesterase) inhibitor | |
| dibenzoylmethane | dibenzoylmethane : A beta-diketone that is acetylacetone (acac) in which both methyl groups have been replaced by phenyl groups. It is a minor constituent of the root extract of licorice (Glycyrrhiza glabra) and exhibits antimutagenic and anticancer effects. | aromatic ketone; beta-diketone | antimutagen; antineoplastic agent; metabolite |
| benzil | benzil : An alpha-diketone that is ethane-1,2-dione substituted by phenyl groups at positions 1 and 2 respectively. benzil: structure | alpha-diketone; aromatic ketone | |
| phenyl trifluoromethyl ketone | phenyl trifluoromethyl ketone: converted to trifluoroacetic acid in water | ||
| 1,3-cyclohexanedione | 1,3-cyclohexanedione: structure cyclohexane-1,3-dione : A cyclohexanedione carrying oxo substituents at positions 1 and 3. | beta-diketone; cyclohexanedione | |
| oleanolic acid | hydroxy monocarboxylic acid; pentacyclic triterpenoid | plant metabolite | |
| dibromsalicil | dibromsalicil: brominated salicyclic acid deriv; antiplaque antiseptic | ||
| 1,2-naphthoquinone | 1,2-naphthoquinone : The parent structure of the family of 1,2-naphthoquinones, in which the oxo groups of the quinone moiety are at positions 1 and 2 of the naphthalene ring. It is a metabolite of naphthalene and is found in diesel exhaust particles. naphthalene-1,2-dione: structure given in first source | 1,2-naphthoquinones | aryl hydrocarbon receptor agonist; carcinogenic agent |
| 1-acetylisatin | 1-acetylisatin: structure in first source | indoledione | |
| 1-phenyl-1,2-propanedione | 1-phenyl-1,2-propanedione : An alpha-diketone that consists of 1-phenylpropane bearing keto substituents at positions 1 and 2. It is found in coffee. 1-phenyl-1,2-propanedione: an oxoglutarate carrier antagonist | alpha-diketone; aromatic ketone | plant metabolite |
| 2,3-pentanedione | pentane-2,3-dione : An alpha-diketone that is pentane substituted at the 2- and 3-positions by oxo groups. | alpha-diketone; methyl ketone | flavouring agent |
| 5-methylisatin | 5-methylisatin: structure in first source | ||
| 1,2-cyclohexanedione | cyclohexane-1,2-dione : A cyclohexanedione carrying oxo substituents at positions 1 and 2. cyclohexanedione : Cyclohexanones carrying two oxo substituents. | cyclohexanedione | |
| 4-nitrophenyl acetate | C-nitro compound; phenyl acetates | ||
| n-methylisatin | N-methylisatin: structure given in first source | ||
| 9-amino-6-chloro-2-methoxyacridine | |||
| acetylacetone | acetylacetone : A beta-diketone that is pentane in which the hydrogens at positions 2 and 4 are replaced by oxo groups. | beta-diketone | |
| 5-Methoxyisatin | indoles | anticoronaviral agent | |
| quinapril | quinapril : A member of the class of isoquinolines that is (3S)-2-L-alanyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid in which the alpha-amino group of the alanyl residue has been substituted by a 1-ethoxycarbonyl-4-phenylbutan-2-yl group (the all-S isomer). A prodrug for quinaprilat (by hydrolysis of the ethyl ester to the corresponding carboxylic acid), it is used as an angiotensin-converting enzyme inhibitor (ACE inhibitor) used (generally as the hydrochloride salt) for the treatment of hypertension and congestive heart failure. Quinapril: A tetrahydroisoquinoline derivative and ANGIOTENSIN CONVERTING ENZYME inhibitor that is used in the treatment of HYPERTENSION and HEART FAILURE. | dicarboxylic acid monoester; ethyl ester; isoquinolines; tertiary carboxamide | antihypertensive agent; EC 3.4.15.1 (peptidyl-dipeptidase A) inhibitor; prodrug |
| cilazapril, anhydrous | cilazapril : A pyridazinodiazepine resulting from the formal condensation of the carboxy group of cilazaprilat with ethanol. It is a drug used in the treatment of hypertension and heart failure. Cilazapril: One of the ANGIOTENSIN-CONVERTING ENZYME INHIBITORS (ACE inhibitors) used for hypertension. It is a prodrug that is hydrolyzed after absorption to its main metabolite cilazaprilat. | dicarboxylic acid monoester; ethyl ester; pyridazinodiazepine | antihypertensive agent; EC 3.4.15.1 (peptidyl-dipeptidase A) inhibitor; prodrug |
| clopidogrel | clopidogrel : A thienopyridine that is 4,5,6,7-tetrahydrothieno[3,2-c]pyridine in which the hydrogen attached to the nitrogen is replaced by an o-chlorobenzyl group, the methylene hydrogen of which is replaced by a methoxycarbonyl group (the S enantiomer). A P2Y12 receptor antagonist, it is used to inhibit blood clots and prevent heart attacks. Clopidogrel: A ticlopidine analog and platelet purinergic P2Y receptor antagonist that inhibits adenosine diphosphate-mediated PLATELET AGGREGATION. It is used to prevent THROMBOEMBOLISM in patients with ARTERIAL OCCLUSIVE DISEASES; MYOCARDIAL INFARCTION; STROKE; or ATRIAL FIBRILLATION. | methyl ester; monochlorobenzenes; thienopyridine | anticoagulant; P2Y12 receptor antagonist; platelet aggregation inhibitor |
| irinotecan | carbamate ester; delta-lactone; N-acylpiperidine; pyranoindolizinoquinoline; ring assembly; tertiary alcohol; tertiary amino compound | antineoplastic agent; apoptosis inducer; EC 5.99.1.2 (DNA topoisomerase) inhibitor; prodrug | |
| capecitabine | capecitabine : A carbamate ester that is cytidine in which the hydrogen at position 5 is replaced by fluorine and in which the amino group attached to position 4 is converted into its N-(penyloxy)carbonyl derivative. Capecitabine is a antineoplastic agent used in the treatment of cancers. Capecitabine: A deoxycytidine derivative and fluorouracil PRODRUG that is used as an ANTINEOPLASTIC ANTIMETABOLITE in the treatment of COLON CANCER; BREAST CANCER and GASTRIC CANCER. | carbamate ester; cytidines; organofluorine compound | antimetabolite; antineoplastic agent; prodrug |
| 3-methyl-1,2-cyclopentanedione | 3-methyl-1,2-cyclopentanedione: a peroxynitrite scavenger isolated from coffee extract; structure in first source | cyclic ketone | |
| ursolic acid | hydroxy monocarboxylic acid; pentacyclic triterpenoid | geroprotector; plant metabolite | |
| oseltamivir | oseltamivir : A cyclohexenecarboxylate ester that is the ethyl ester of oseltamivir acid. An antiviral prodrug (it is hydrolysed to the active free carboxylic acid in the liver), it is used to slow the spread of influenza. Oseltamivir: An acetamido cyclohexene that is a structural homolog of SIALIC ACID and inhibits NEURAMINIDASE. | acetamides; amino acid ester; cyclohexenecarboxylate ester; primary amino compound | antiviral drug; EC 3.2.1.18 (exo-alpha-sialidase) inhibitor; environmental contaminant; prodrug; xenobiotic |
| alpha-furil | alpha-furil: structure in first source | ||
| 4-benzoylbenzoic acid | 4-carboxybenzophenone: a photosensitizer agent | ||
| 1,10-phenanthroline-5,6-dione | 1,10-phenanthroline-5,6-dione: has antineoplastic, intercalating, and trypanocidal activities; structure given in first source | ||
| 2-chloranil | |||
| 4-nitrophenyl butyrate | p-nitrophenyl butyrate : A butyrate ester resulting from the formal condensation of the hydroxy group of 4-nitrophenol with the carboxy group of butyric acid. | butyrate ester; C-nitro compound | |
| 3,5-di-tert-butyl-1,2-benzoquinone | |||
| gamma-glutamine-4-nitroanilide | gamma-glutamine-4-nitroanilide: substrate for glutaminase B.; RN given refers to (L)-isomer | ||
| 5-Chloro-1H-indole-2,3-dione | indoles | anticoronaviral agent | |
| 5-iodoisatin | 5-iodoisatin: structure in first source | indoles | anticoronaviral agent |
| 2,2-dimethoxy-2-phenylacetophenone | |||
| anisoin | |||
| hydrobenzoin | hydrobenzoin: structure in first source | ethanediol | |
| tanshinone | tanshinone: from root of Salvia miltiorrhiza Bunge; RN given refers to tanshinone I; cardioprotective agent and neuroprotective agent | abietane diterpenoid | anticoronaviral agent |
| san 58035 | |||
| 1,3-indandione | 1,2-indanedione: use for detection of latent fingerprints on porous surfaces; structure in first source | ||
| 3-octylthio-1,1,1-trifluoro-2-propanone | 3-octylthio-1,1,1-trifluoro-2-propanone: a pesticide synergist; inhibits juvenile hormone esterase | ||
| dexmethylphenidate | dexmethylphenidate : A methyl phenyl(piperidin-2-yl)acetate in which both stereocentres have R configuration. It is the active enantiomer in the racemic drug methylphenidate. | methyl phenyl(piperidin-2-yl)acetate | adrenergic agent |
| miltirone | miltirone: from Salvis miltiorrhiza Bunge; central benzodiazepine receptor ligand; structure given in first source | abietane diterpenoid | |
| cryptotanshinone | cryptotanshinone: from Salvia miltiorrhiza | abietane diterpenoid | anticoronaviral agent |
| ibuprofen acyl glucuronide | ibuprofen acyl glucuronide: structure given in first source; metabolite of ibuprofen; 13% of ibuprofen administered to humans is excreted in urine as its acyl glucuronide | terpene glycoside | |
| tanshinone ii a | tashinone IIA: a cardiovascular agent with antineoplastic activity; isolated from Salvia miltiorrhiza; structure in first source | abietane diterpenoid | |
| naproxen glucuronide | naproxen glucuronide: structure in first source | ||
| 5-Fluoroisatin | indoles | anticoronaviral agent | |
| lupeol | pentacyclic triterpenoid; secondary alcohol | anti-inflammatory drug; plant metabolite | |
| temocapril | dipeptide | ||
| cocaine | cocaine : A tropane alkaloid obtained from leaves of the South American shrub Erythroxylon coca. Cocaine: An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. | benzoate ester; methyl ester; tertiary amino compound; tropane alkaloid | adrenergic uptake inhibitor; central nervous system stimulant; dopamine uptake inhibitor; environmental contaminant; local anaesthetic; mouse metabolite; plant metabolite; serotonin uptake inhibitor; sodium channel blocker; sympathomimetic agent; vasoconstrictor agent; xenobiotic |
| 1-[(3,4-dichlorophenyl)methyl]indole-2,3-dione | indoles | ||
| 5-Nitroisatin | indoles | anticoronaviral agent | |
| delapril | delapril: RN refers to HCl; structure given in first source | peptide | |
| benazepril | benazepril : A benzazepine that is benazeprilat in which the carboxy group of the 2-amino-4-phenylbutanoic acid moiety has been converted to the corresponding ethyl ester. It is used (generally as its hydrochloride salt) as a prodrug for the angiotensin-converting enzyme inhibitor benazeprilat in the treatment of hypertension and heart failure. benazepril: structure given in first source | benzazepine; dicarboxylic acid monoester; ethyl ester; lactam | EC 3.4.15.1 (peptidyl-dipeptidase A) inhibitor; prodrug |
| heroin | heroin : A morphinane alkaloid that is morphine bearing two acetyl substituents on the O-3 and O-6 positions. As with other opioids, heroin is used as both an analgesic and a recreational drug. Frequent and regular administration is associated with tolerance and physical dependence, which may develop into addiction. Its use includes treatment for acute pain, such as in severe physical trauma, myocardial infarction, post-surgical pain, and chronic pain, including end-stage cancer and other terminal illnesses. Heroin: A narcotic analgesic that may be habit-forming. It is a controlled substance (opium derivative) listed in the U.S. Code of Federal Regulations, Title 21 Parts 329.1, 1308.11 (1987). Sale is forbidden in the United States by Federal statute. (Merck Index, 11th ed) | morphinane alkaloid | mu-opioid receptor agonist; opioid analgesic; prodrug |
| 6-o-monoacetylmorphine | 6-O-monoacetylmorphine: RN given refers to parent cpd(5alpha,6alpha)-isomer | morphinane alkaloid | |
| imidapril | imidapril : A member of the class of imidazolidines that is (4S)-1-methyl-2-oxoimidazolidine-4-carboxylic acid in which the hydrogen of the imidazolidine nitrogen has been substituted by (1S)-1-{[(2S)-1-ethoxy-1-oxo-4-phenylbutan-2-yl]amino}ethyl group. It is the prodrug for imidaprilat, an ACE inhibitor used for the treatment of chronic heart failure. imidapril: structure given in first source | dicarboxylic acid monoester; dipeptide; ethyl ester; imidazolidines; N-acylurea; secondary amino compound | antihypertensive agent; EC 3.4.15.1 (peptidyl-dipeptidase A) inhibitor; prodrug |
| ol-135 | |||
| Dihydrotanshinone I | dihydrotanshinone I: extracted from Radix Salviae | abietane diterpenoid | anticoronaviral agent |
| t-tucb | |||
| 23-hydroxybetulinic acid | 23-hydroxybetulinic acid: structure in first source | triterpenoid | metabolite |
| tanshinone ii a sodium sulfonate | tanshinone II A sodium sulfonate: has cardioprotective activity; water-soluble derivative of tanshinone II A; isolated from Salvia militiorrhiza; relieves anginal pain; structure |