Lecithin cholesterol acyltransferase
| Lecithin cholesterol acyltransferase | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 416 amino acids | |
| Identifier | ||
| Gene name | LCAT | |
| External IDs | ||
| Enzyme classification | ||
| EC, category | 2.3.1.43 , transferase | |
| Response type | Transfer of fatty acids to sterols | |
| Substrate | Phosphatidylcholine + sterol | |
| Products | 1-acylglycerophosphocholine + sterol ester | |
| Occurrence | ||
| Homology family | Acylceramide synthase | |
| Parent taxon | Euteleostomi | |
Lecithin cholesterol acyltransferase ( LCAT for short ) is the enzyme in terrestrial vertebrates for the formation of cholesterol esters from cholesterol and lecithin . 70 percent of the cholesterol transported in the human blood in lipoproteins is present as cholesterol esters, so the liver can break it down more easily. LCAT is therefore indispensable in lipid metabolism . Mutations in the LCAT gene can cause hereditary LCAT deficiency (very rare) , which is the cause of familial HDL deficiency and fisheye disease .
LCAT is produced in the liver and released into the blood. There it binds to and is located on the surface of HDL particles and takes up cholesterol and phosphatidylcholine from chylomicrons , VLDL residues and dead cells or degraded membranes ("cholesterol scavengers"). It also enables the HDL particles to absorb cholesterol from extrahepatic tissues and thus to reverse cholesterol transport (RCT).
Catalyzed reaction
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A fatty acid residue from lecithin is transferred to cholesterol. Palmitoyl, oleoyl and linoleoyl are possible residues, while other sterols besides cholesterol can also act as recipients.
Web links
Individual evidence
- ↑ UniProt P04180
- ↑ Biorama: The Lipids ( Memento from September 18, 2007 in the Internet Archive )