Heme oxygenase 2 is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that in humans is encoded by the ''HMOX2''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Function

Heme oxygenase Heme oxygenase, or haem oxygenase, (HMOX, commonly abbreviated as HO) is an enzyme that catalyzes the degradation of heme to produce biliverdin, ferrous ion, and carbon monoxide. There are many heme degrading enzymes in nature. In general, only ...

, an essential enzyme in

heme Heme, or haem (pronounced / hi:m/ ), is a precursor to hemoglobin, which is necessary to bind oxygen in the bloodstream. Heme is biosynthesized in both the bone marrow and the liver. In biochemical terms, heme is a coordination complex "consisti ...

catabolism, cleaves heme to form

biliverdin Biliverdin (latin for green bile) is a green tetrapyrrolic bile pigment, and is a product of heme catabolism.Boron W, Boulpaep E. Medical Physiology: a cellular and molecular approach, 2005. 984-986. Elsevier Saunders, United States. It is the pi ...

, which is subsequently converted to bilirubin by

biliverdin reductase Biliverdin reductase (BVR) is an enzyme () found in all tissues under normal conditions, but especially in reticulo-macrophages of the liver and spleen. BVR facilitates the conversion of biliverdin to bilirubin via the reduction of a double-b ...

, and

carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

, a putative neurotransmitter. Heme oxygenase activity is induced by its substrate heme and by various nonheme substances. Heme oxygenase occurs as 2

isozyme In biochemistry, isozymes (also known as isoenzymes or more generally as multiple forms of enzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. Isozymes usually have different kinetic parameters (e.g. dif ...

s, an inducible heme oxygenase-1 and a constitutive heme oxygenase-2.

HMOX1 ''HMOX1'' (heme oxygenase 1 gene) is a human gene that encodes for the enzyme heme oxygenase 1 (). Heme oxygenase (abbreviated HMOX or HO) mediates the first step of heme catabolism, it cleaves heme to form biliverdin. The ''HMOX'' gene is locate ...

and HMOX2 (this enzyme) belong to the heme oxygenase family.

Function

References

Further reading