Apyrase
   HOME

TheInfoList



OR:

Apyrase (, ''ATP-diphosphatase'',
adenosine Adenosine ( symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside building ...
diphosphatase, ''ADPase'', ''ATP diphosphohydrolase'') is a
calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...
-activated plasma membrane-bound
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 ...
(magnesium can also activate it) () that catalyses the
hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...
of ATP to yield
AMP #REDIRECT Amp #REDIRECT Amp {{Redirect category shell, {{R from other capitalisation{{R from ambiguous page ...
{{Redirect category shell, {{R from other capitalisation{{R from ambiguous page ...
and
inorganic phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosphor ...
. 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 Pyrosequencing is a method of DNA sequencing (determining the order of nucleotides in DNA) based on the "sequencing by synthesis" principle, in which the sequencing is performed by detecting the nucleotide incorporated by a DNA polymerase. Pyrosequ ...
. The salivary apyrases of blood-feeding
arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
s are
nucleotide Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules wi ...
hydrolysing
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 ...
s that are implicated in the inhibition of host
platelet aggregation Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby ini ...
through the
hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...
of
extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...
adenosine diphosphate Adenosine diphosphate (ADP), also known as adenosine pyrophosphate (APP), is an important organic compound in metabolism and is essential to the flow of energy in living cells. ADP consists of three important structural components: a sugar backbon ...
.


References


External links

* Protein families EC 3.6.1 {{3.6-enzyme-stub