Sulfite oxidase

Sulfite oxidase
Properties of human protein
Mass / length primary structure	466 amino acids
Secondary to quaternary structure	Homodimer
Cofactor	Heme , molybdopterin
Identifier
Gene name	SUOX
External IDs	OMIM : 606887 ; UniProt : P51687 ;
Enzyme classification
EC, category	1.8.3.1 , oxidoreductase
Response type	Hydroxylation
Substrate	Sulfite + H 2 O + O 2
Products	Sulfate + H 2 O 2
Occurrence
Homology family	Xanthine dehydrogenase
Parent taxon	Creature
	Orthologue

The sulphite is an enzyme , and which, which is found in most living organisms, the reaction of sulfite to sulfate catalyzed. It is localized in the mitochondria of all eukaryotes . A related sulfite oxidase can also be found in many types of bacteria. In mammals , sulfite oxidase occurs primarily in the liver, kidneys, spleen, lungs, brain and heart.

function

70–95% of the sulfite ingested normally ends up in the bloodstream. There it is oxidized to sulphate by sulphite oxidase and the electrons are transported via cytochrome c ( electron transport chain ) with the aim of obtaining ATP:

{\ displaystyle \ mathrm {SO_ {3} ^ {2 -} + \ H_ {2} O \ \ rightleftharpoons \ SO_ {4} ^ {2 -} + 2H ^ {+} + 2e ^ {-}}}

The sulfates formed are excreted in the urine.

Sulphite oxidase deficiency

Sulphite oxidase deficiency leads to therapy-resistant newborn seizures (epilepsy) and severe encephalopathy. The cause of a deficiency is either an isolated enzyme defect or a molybdenum cofactor deficiency, whereby the clinical pictures cannot be distinguished from one another.

Isolated enzyme defect :

The oxidation of sulfite to sulfate is disturbed, which results in an increase in the sulfite concentration in all body fluids.

Molybdenum Cofactor Deficiency ( see Molybdenum Cofactor Deficiency ):

The synthesis of the molybdenum cofactor or molybdopterin is disturbed, so that the activity of the enzymes sulfite oxidase, xanthine oxidase and aldehyde oxidase is restricted. Molybdate supplementation is a possible therapy.

Individual evidence

^ Roche Lexicon Medicine, 5th, Urban and Fischer edition , Munich 2003.

↑ Fröscher, Vasselle, Hufnagel: Die Epilepsien Schattauer, Stuttgart 2004.

^ Witkowski, Prokop: "Lexicon of Syndromes and Malformations, 7th Edition" Springer, Berlin - Heidelberg 2003.

↑ OrphaNet: Encephalopathy due to sulphite oxidase deficiency.

Web links

Wikibooks: Biochemistry and Pathobiochemistry: Sulfur - Learning and Teaching Materials

[1] Roche Lexicon Medicine, 5th, Urban and Fischer edition , Munich 2003.

[2] Fröscher, Vasselle, Hufnagel: Die Epilepsien Schattauer, Stuttgart 2004.

[3] Witkowski, Prokop: "Lexicon of Syndromes and Malformations, 7th Edition" Springer, Berlin - Heidelberg 2003.

[4] OrphaNet: Encephalopathy due to sulphite oxidase deficiency.