Primary-amine oxidase, also known as semicarbazide-sensitive amine oxidase (SSAO), 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 ...

() with the

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

''primary-amine:oxygen oxidoreductase (deaminating)''. This enzyme catalyses the following

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

: RCH₂NH₂ + H₂O + O₂

\rightleftharpoons

RCHO + NH₃ + H₂O₂ These enzymes are copper quinoproteins (2,4,5-trihydroxyphenylalanine quinone). Like

monoamine oxidase Monoamine oxidases (MAO) () are a family of enzymes that catalyze the oxidation of monoamines, employing oxygen to clip off their amine group. They are found bound to the outer membrane of mitochondria in most cell types of the body. The first ...

(MAO), SSAO can deaminate short-chain primary amines, but is insensitive to MAO inhibitors.

Semicarbazide Semicarbazide is the chemical compound with the formula OC(NH2)(N2H3). It is a water-soluble white solid. It is a derivative of urea. Synthesis The compound prepared by treating urea with hydrazine:Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazi ...

inhibits the enzyme, in addition to other

hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...

hydroxylamine Hydroxylamine is an inorganic compound with the formula . The material is a white crystalline, hygroscopic compound.Greenwood and Earnshaw. ''Chemistry of the Elements.'' 2nd Edition. Reed Educational and Professional Publishing Ltd. pp. 431–43 ...

and propargylamine. However, hydrazines are weak inhibitors and stronger inhibitors have been developed. SSAO is found in the smooth muscle of blood vessels and various other tissues. The physiological function of SSAO is not well understood. Development of blood vessels, lipolysis regulation, and detoxication are suggested. It may function as a scavenger enzyme to assist MAO. However, the oxidation process generates harmful products that may be involved in causing atherosclerosis and vascular damage in diabetes. Elevation of SSAO activity is observed in

atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheroma, atheromatous plaque. At onset there are usu ...

diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

obesity Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's we ...

carotid plaque In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid"
in
varicosities A neuroeffector junction is a site where a motor neuron releases a neurotransmitter to affect a target—non-neuronal—cell. This junction functions like a synapse. However, unlike most neurons, somatic efferent motor neurons innervate skeletal mu ...

. There are SSAO inhibitors in development.

Human proteins containing this domain

AOC2 Amine oxidase, copper containing 2 (AOC2) is a protein that in humans is encoded by the ''AOC2'' gene. The protein is a copper-containing primary amine oxidase enzyme. Function Copper amine oxidases catalyze the oxidative conversion of amines t ...

AOC3 Amine oxidase, copper containing 3 (AOC3), also known as vascular adhesion protein (VAP-1) and HPAO is an enzyme that in humans is encoded by the AOC3 gene on chromosome 17. This protein is a member of the semicarbazide-sensitive amine oxidase (S ...

Bacterial proteins containing this domain

*Tyramine oxidase ( tynA) in ''

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

References

External links

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