Acyloxyacyl hydrolase
| acyloxyacyl hydrolase | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| EC number | 3.1.1.77 | ||||||
| Databases | |||||||
| IntEnz | IntEnz view | ||||||
| BRENDA | BRENDA entry | ||||||
| ExPASy | NiceZyme view | ||||||
| KEGG | KEGG entry | ||||||
| MetaCyc | metabolic pathway | ||||||
| PRIAM | profile | ||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||
| Gene Ontology | AmiGO / EGO | ||||||
|
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In enzymology, an acyloxyacyl hydrolase (EC 3.1.1.77) is an enzyme that catalyzes the chemical reaction
- 3-(acyloxy)acyl group of bacterial lipopolysaccharide (lipid A moiety)
3-hydroxyacyl group of bacterial lipopolysaccharide + a fatty acid
Hence, this enzyme has one substrate, the 3-(acyloxy)acyl groups of bacterial lipopolysaccharides, and two products, [partially deacylated lipopolysaccharide] and fatty acid.
The enzyme removes from lipid A the secondary acyl chains that are needed for lipopolysaccharides to be recognized by the MD-2--TLR4 receptor on animal cells. This reaction inactivates the lipopolysaccharide (endotoxin). Acyloxyacyl hydrolase is produced by monocyte-macrophages, neutrophils, dendritic cells, and renal cortical epithelial cells. It is a protein of Mr = ~60,000 that has two disulfide-linked subunits.
This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name of this enzyme class is '.
References
- Erwin AL, Munford RS (1990). "Deacylation of structurally diverse lipopolysaccharides by human acyloxyacyl hydrolase". J. Biol. Chem. 265 (27): 16444–9. PMID 2398058.
- Hagen, F., O'Hara PJ, Munford RS (1991). "Expression and characterization of recombinant human acyloxyacyl hydrolase, a leukocyte enzyme that deacylates bacterial lipopolysaccharides". Biochemistry. 30 (34): 8415–8423. doi:10.1021/bi00098a020. PMID 1883828.
- Munford RS, Hunter JP (1992). "Acyloxyacyl hydrolase, a leukocyte enzyme that deacylates bacterial lipopolysaccharides, has phospholipase, lysophospholipase, diacylglycerollipase, and acyltransferase activities in vitro". J. Biol. Chem. 267 (14): 10116–21. PMID 1577781.