New!
ADK Screening Assay Kit
A non-isotopic and high-performance assay (Z'-factor = 0.68) for a fast and simple measurement of adenosine kinase (ADK) activity in vitro.

Award!
Dr Larissa Balakireva, CEO & Founder of NovoCIB, was awarded with the Trophy of
"Femmes en Or 2011, Femme de l'Innovation"
in September 2011
.


NOVOCIB is certified by the French Ministry of Research as a "Research Tax Credit"
(Crédit Impôt Recherche - CIR) company.
To know more:
• French Ministry of Research (in French)
• Press Release


Ref. #E-Nov5
Quantity Price*
25 mUnits ** € 195.00
100 mUnits € 590.00
0.5 Unit € 2490.00
Human Recombinant Adenosine Kinase (AK)
(E.C.2.7.1.20)

* Pricing updated September 23rd, 2011. Prices are subject to change without notice. Shipping charges are not included.
** One unit of adenosine kinase converts 1.0 µmole of inosine and ATP to IMP and ADP per minute at pH 8 at 37°C, as measured by a coupled IMPDH enzyme system. Specific Activity: ≥ 30 mU/mg protein.
For other size, please contact us

Click to order or to get further information


Human Recombinant AK - Product description

Synonyms: ADK, Adenosine 5'-phosphotransferase

NOVOCIB's human adenosine kinase (AK) is a recombinant protein of ca. 39kDa (345-aa short form(1,2) cloned by RT-PCR amplification of mRNA extracted from human hepatoma cells and expressed in E.coli. The sequence of the cloned AK (GenBank accession number U50196) was confirmed by DNA sequencing (100% identity).
Adenosine kinase is a ubiquitous enzyme that catalyzes the transfer of γ-phosphate from ATP to 5’-hydroxyl of adenosine generating AMP and ADP. Adenosine (AR) is an important modulator of central nervous system functions with a half-life of seconds. Facilitated diffusion of adenosine across the cell membrane closely couples adenosine concentrations in the intracellular and extracellular compartments. Inhibition of adenosine kinase results in selective increase of local adenosine concentrations and reduced seizure susceptibility and nociception in vivo(3). Adenosine kinase is an attractive and experimentally validated target for the development of new analgesic and anti-inflammatory agents(4). In addition, AK has recently emerged as a novel target to predict and to prevent epileptogenesis(5,6), to treat schizophrenia(7) or to limit brain injury after an ischemic stroke(8). The X-ray crystallographic structure of human AK has been described(9) and provides structural basis for rational design and optimisation of new AK inhibitors.
In addition, this enzyme is responsible for the phosphorylation and consequent clinical activity of several therapeutically useful nucleosides, including the antiviral drug ribavirin(10), immunosuppressive drug mizoribine(11), and anticancer C-nucleoside, tiazofurin(12).
Storage:–20 °C in a solution containing 50 mM Tris-HCl, pH 7.6, 1 mM β-mercaptoethanol, 50% glycerol.

Unit Definition: One unit of adenosine kinase converts 1.0 µmole of inosine and ATP to IMP and ADP per minute at pH 8 at 37°C, as measured by a coupled IMPDH enzyme system.
(see ADK Screening Assay Kit or AK Inhibition Screening for further details)

Specific Activity: ≥ 0.030 unit/mg protein.

Purity: controlled by 10% AA SDS-PAGE. 		Assay condition: Enzymatic activity of adenosine kinase with particular nucleoside substrate is measured by spectrophotometric assays in a coupled lactate dehydrogenase / pyruvate kinase system. Assays were carried out at 37°C, at 50mM Tris-HCl pH7,6; 50mM KCl, 5mM MgCl2, 2.5mM ATP, 0.1mM NADH, 1mM phosphoenolpyruvate, 1mM DTT, PK 5U/ml, LDH 5U/ml. Reaction was followed in an iEMS Reader MF (Labsystems) microtiter plate reader at 340nm. Nucleosides, nucleotides, LDH and PK were purchased from Sigma-Aldrich.
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References (with links to PubMed)
1. J. Spychala et al. (1996): Cloning of human adenosine kinase cDNA: Sequence similarity to microbial ribokinases and fructokinases Proc. Natl. Acad. Sci. USA 93(3), 1232-1237
2. B. Sahin et al. (2004): Molecular characterization of recombinant mouse adenosine kinase and evaluation as a target for protein phosphorylation Eur. J. Biochem. 271(17), 3547-3555
3. M. F. Jarvis et al. (2000): ABT-702 (4-amino-5-(3-bromophenyl)-7-(6-morpholinopyridin-3-yl)pyrido[2, 3-d]pyrimidine), a novel orally effective adenosine kinase inhibitor with analgesic and anti-inflammatory properties: I. In vitro characterization and acute antinociceptive effects in the mouse J. Pharmacol. Exp. Ther. 295(3), 1156-1164
4. S. McGaraughty et al. (2005): Anticonvulsant and antinociceptive actions of novel adenosine kinase inhibitors Curr. Top. Med. Chem. 5(1):43-58
5. D. E. Fedele et al. (2005): Astrogliosis in epilepsy leads to overexpression of adenosine kinase, resulting in seizure aggravation Brain 128(Pt 10), 2383-2395
6. D. Boison (2008): The adenosine kinase hypothesis of epileptogenesis Prog. Neurobiol. 84(3), 249-262
7. D. Boison et al. (2011): Adenosine hypothesis of schizophrenia – Opportunities for pharmacotherapy doi:10.1016/J.neuropharm.2011.01.048
8. H. Y. Shen et al. (2011): Adenosine kinase determines the degree of brain injury after ischemic stroke in mice J. Cereb. Blood Flow Metab. 31(7): 1648-1659
9. I. I. Mathews et al. (1998): Structure of human adenosine kinase at 1.5 A resolution Biochemistry 37(45): 15607-602
10. R. C. Willis et al. (1978): Adenosine kinase initiates the major route of ribavirin activation in a cultured human cell Proc. Natl. Acad. Sci. USA 75(7), 3042-3044
11. R. L. Miller et al. (1979): Adenosine kinase from rabbit liver. II. Substrate and inhibitor specificity J. Biol. Chem., 254(7), 2346–2352 12. P. P. Saunders et al. (1990): Tiazofurin is phosphorylated by three enzymes from Chinese hamster ovary cells Cancer Res. 50(17), 5269-5274
Download this document "NovoCIB's Adenosine kinase" 
To know more about our Nucleoside kinases catalogue.


Related Links
• ADK Screening Assay Kit
• AK Inhibition Assays
• Nucleoside Kinases
• Nucleoside Kinase - IMPDH coupled assay 		• Phosphorylation of Nucleoside Analogues:
  In vitro Assay Services
• dCK enzyme
• CMK enzyme
• cN-II enzyme
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