Enzymes
| UniProtKB help_outline | 5 proteins |
Reaction participants Show >> << Hide
- Name help_outline (24S)-hydroxycholesterol Identifier CHEBI:34310 (Beilstein: 3218472; CAS: 474-73-7) help_outline Charge 0 Formula C27H46O2 InChIKeyhelp_outline IOWMKBFJCNLRTC-XWXSNNQWSA-N SMILEShelp_outline [H][C@@]1(CC[C@@]2([H])[C@]3([H])CC=C4C[C@@H](O)CC[C@]4(C)[C@@]3([H])CC[C@]12C)[C@H](C)CC[C@H](O)C(C)C 2D coordinates Mol file for the small molecule Search links Involved in 8 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 1-hexadecanoyl-2-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphocholine Identifier CHEBI:73002 (CAS: 6931-84-6) help_outline Charge 0 Formula C42H80NO8P InChIKeyhelp_outline JLPULHDHAOZNQI-ZTIMHPMXSA-N SMILEShelp_outline C(C[N+](C)(C)C)OP(=O)([O-])OC[C@H](OC(CCCCCCC/C=C\C/C=C\CCCCC)=O)COC(=O)CCCCCCCCCCCCCCC 2D coordinates Mol file for the small molecule Search links Involved in 15 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline (24S)-hydroxycholesterol 3-linoleoate Identifier CHEBI:82875 Charge 0 Formula C45H76O3 InChIKeyhelp_outline MATQTXQZPPLBEJ-KTBYLDBTSA-N SMILEShelp_outline CCCCC\C=C/C\C=C/CCCCCCCC(=O)O[C@H]1CC[C@]2(C)[C@H]3CC[C@]4(C)[C@H](CC[C@H]4[C@@H]3CC=C2C1)[C@H](C)CC[C@H](O)C(C)C 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 1-hexadecanoyl-sn-glycero-3-phosphocholine Identifier CHEBI:72998 (CAS: 14863-27-5) help_outline Charge 0 Formula C24H50NO7P InChIKeyhelp_outline ASWBNKHCZGQVJV-HSZRJFAPSA-N SMILEShelp_outline [C@@H](COC(=O)CCCCCCCCCCCCCCC)(COP(OCC[N+](C)(C)C)(=O)[O-])O 2D coordinates Mol file for the small molecule Search links Involved in 77 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:43224 | RHEA:43225 | RHEA:43226 | RHEA:43227 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
|
Publications
-
The enzyme lecithin-cholesterol acyltransferase esterifies cerebrosterol and limits the toxic effect of this oxysterol on SH-SY5Y cells.
La Marca V., Spagnuolo M.S., Cigliano L., Marasco D., Abrescia P.
Cholesterol is mostly removed from the CNS by its conversion to cerebrosterol (24(S)-hydroxycholesterol, 24(S)OH-C), which is transported to the circulation for bile formation in liver. A neurotoxic role of this oxysterol was previously demonstrated in cell culture. Here, we provide evidence that ... >> More
Cholesterol is mostly removed from the CNS by its conversion to cerebrosterol (24(S)-hydroxycholesterol, 24(S)OH-C), which is transported to the circulation for bile formation in liver. A neurotoxic role of this oxysterol was previously demonstrated in cell culture. Here, we provide evidence that the enzyme lecithin-cholesterol acyltransferase, long known to esterify cholesterol, also produces monoesters of 24(S)OH-C. Proteoliposomes containing apolipoprotein A-I or apolipoprotein E were used to stimulate the enzyme activity and entrap the formed esters. Proteoliposomes with apolipoprotein A-I were found to be more active than those with apolipoprotein E in stimulating the production of oxysteryl esters. Cholesterol and 24(S)OH-C were found to compete for enzyme activity. High levels of haptoglobin, as those circulating during the acute inflammatory phase, inhibited 24(S)OH-C esterification. When highly neurotoxic 24(S)OH-C was treated with enzyme and proteoliposomes before incubation with differentiated SH-SY5Y cells, the neuron survival improved. The esters of 24(S)OH-C, embedded into proteoliposomes by the enzyme and isolated from unesterified 24(S)OH-C by gel filtration chromatography, did not enter the neurons in culture. These results suggest that the enzyme, in the presence of the apolipoproteins, converts 24(S)OH-C into esters restricted to the extracellular environment, thus preventing or limiting oxysterol-induced neurotoxic injuries to neurons in culture. 24-hydroxycholesterol (24(S)OH-C) is neurotoxic. The enzyme lecithin-cholesterol acyltransferase (LCAT) synthesizes monoesters of 24(S)OH-C in reaction mixtures with proteoliposomes containing phospholipids and apolipoprotein A-I or apolipoprotein E. The esters, also produced by incubation of cerebrospinal fluid only with tritiated 24(S)OH-C, are embedded into lipoproteins that do not enter neurons in culture. The enzyme activity limits the toxicity of 24-hydroxycholesterol in neuron culture. << Less
J. Neurochem. 130:97-108(2014) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.