| Apyrase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 structure and protein design of human apyrase | |||||||||
| Identifiers | |||||||||
| Symbol | Apyrase | ||||||||
| Pfam | PF06079 | ||||||||
| InterPro | IPR009283 | ||||||||
| SCOP2 | 1s1d / SCOPe / SUPFAM | ||||||||
| Membranome | 581 | ||||||||
| |||||||||
Apyrase ( EC 3.6.1.5, ATP-diphosphatase, adenosine diphosphatase, ADPase, ATP diphosphohydrolase) is a calcium-activated plasma membrane-bound enzyme (magnesium can also activate it) ( EC 3.6.1.5) that catalyses the hydrolysis of ATP to yield AMP and inorganic phosphate. Two isoenzymes are found in commercial preparations from S. tuberosum. One with a higher ratio of substrate selectivity for ATP:ADP (approx 10) and another with no selectivity (ratio 1).
It can also act on ADP and other nucleoside triphosphates and diphosphates with the general reaction being NTP -> NDP + Pi -> NMP + 2Pi. This is the same activity that has been employed in the degradation of unincorporated nucleosides during pyrosequencing.
The salivary apyrases of blood-feeding arthropods are nucleotide hydrolysing enzymes that are implicated in the inhibition of host platelet aggregation through the hydrolysis of extracellular adenosine diphosphate. [1]
References
- ^ Smith TM, Hicks-Berger CA, Kim S, Kirley TL (October 2002). "Cloning, expression, and characterization of a soluble calcium-activated nucleotidase, a human enzyme belonging to a new family of extracellular nucleotidases". Arch. Biochem. Biophys. 406 (1): 105–15. doi: 10.1016/S0003-9861(02)00420-4. PMID 12234496.
External links
- Apyrase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
