leukotriene A4 hydrolase
Crystallographic structure of LTA4H (rainbow coloredN-terminus = blue,C-terminus = red) complexed with theprotease inhibitorbestatin (space-filling model, carbon = white, oxygen = red, nitrogen = blue) based on thePDB:1HS6​ structure.
Identifiers
Symbol	LTA4H
NCBI gene	4048
HGNC	6710
OMIM	151570
PDB	1SQM
RefSeq	NM_000895
UniProt	P09960
Other data
EC number	3.3.2.6
Locus	Chr. 12q22
Search for Structures Swiss-model Domains InterPro

Leukotriene-A4 hydrolase is an enzyme that catalyzes the reaction which convertsLeukotriene A4 toLeukotriene B4.^[1] It is a bifunctional zincenzyme (EC 3.3.2.6) with different amino acids attached to it to aid in the catalysis of the reaction. It also acts as anaminopeptidase. Leukotriene-A4 hydrolase is a cytosolic protein and is found in almost all mammalian cells, tissues and organelles that have been examined.^[1]

This enzyme belongs to the family ofhydrolases, specifically those acting on ether bonds (ether hydrolases). Thesystematic name of this enzyme class is(7E,9E,11Z,14Z)-(5S,6S)-5,6-epoxyicosa-7,9,11,14-tetraenoate hydrolase. Other names in common use includeLTA4 hydrolase,LTA4H, andleukotriene A4 hydrolase. This enzyme participates inarachidonic acid metabolism.^{[citation needed]}

Leukotriene A4 Hydrolase catalyzes the reaction which converts leukotriene A4 to leukotriene B4. TheLeukotriene A4 structure contains anepoxide ring functional group, which are highly reactive due to its ring strain making them extremely electrophilic. This drives the reaction forward, favouring the products Leukotriene B4. Leukotriene A4 hydrolase adds a water molecule across the epoxide ring onLeukotriene A4. The addition of the water molecule opens the epoxide ring and causes the formation of theHydroxy group at the carbon attached to the oxygen from the epoxide. The second carbon involved in the epoxide ring remains the same resulting in leukotriene B4. The water molecule attacking the double bond also forms into a hydroxy group after work-up. The product of the reaction isLeukotriene B4.^{[citation needed]}

As of late 2007, 4structures have been solved for this class of enzymes, withPDB accession codes1GW6,1H19,1HS6, and1SQM.

• leukotriene A4 hydrolase at the U.S. National Library of MedicineMedical Subject Headings (MeSH)

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