kynurenine 3-monooxygenase; kynurenine 3-hydroxylase (KMO)

Function

• kynurenine pathway
• catalyzes the hydroxylation of L-kynurenine to form 3-hydroxy-L-kynurenine, precursor of quinolinate (3 steps), a neurotoxic NMDA receptor antagonist

L-kynurenine + NADPH + O2 <--> 3-hydroxy-L-kynurenine + NADP+ + H2O

Cofactor: FAD

Kinetic parameters:

• Km=24.1 uM for L-kynurenine
• Vmax=8.5 umol/min/mg enzyme
• Optimum pH is 7.5

Structure

• belongs to the aromatic-ring hydroxylase family, KMO subfamily

Compartment

mitochondrial outer membrane

Alternative splicing

named isoforms=3

Expression

expressed in placenta, liver > kidney

Pathology

• increased in neuroinflammatory conditions
• inhibitors may provide new neuroprotective agents

More general terms

• hydroxylase; monooxygenase
• mitochondrial membrane protein
• transmembrane 2 protein
• phosphoprotein

Additional terms

• kynurenine pathway

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=8564
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:8564
• OMIM: https://mirror.omim.org/entry/603538
• UniProt: http://www.uniprot.org/uniprot/O15229.html