Home List of Titles Adenosine kinase from human erythrocytes: determination of the conditions required for assay in crude hemolysates
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/227266
- Adenosine kinase from human erythrocytes: determination of the conditions required for assay in crude hemolysates
- Kyd, Jennelle M.; Bagnara, Aldo S.
- An assay suitable for initial velocity studies was developed to measure adenosine kinase (ATP: adenosine 5'-phosphotransferase, EC 18.104.22.168) activity in crude lysates of human erythrocytes. The pH optimum for the reaction was dependent on the ratio of Mg2+/ATP used in the assay. With a Mg2+/ATP ratio of 5.0, the pH optimum was 5.1 and only 10% of the maximal activity was retained at pH 7.3. When a Mg2+/ATP ratio of 0.50 was used, the pH optimum was 6.2, but 70% of the maximal activity was retained at pH 7.3. For assays performed at pH 7.3, the optimal Mg2+/ATP ratio was 0.50 for ATP concentrations between 0.50 and 2.0 mmol/l. Mg2+ was required for reaction, presumably to form the physiological substrate MgATP2-. However, excess free (uncomplexed) Mg2+ was a strong inhibitor of the enzyme at pH 7.3. At pH 7.3, the K(m) values for adenosine and MgATP2- were 0.66 μmol/l and 82 μmol/l respectively.
- Publication type
- Journal article
- Clinica Chimica Acta, Vol. 103, no. 2 (Apr 1980), pp. 145-153
- Publication year
- FOR Code(s)
- 1103 Clinical Sciences
- Adenosine kinase; Adenosine triphosphate; Blood and hemopoietic system; Coformycin; Divalent cations; Erythrocytes; Haemolysis; Hydrogen-ion concentration; Kinetics; Magnesium; Phosphotransferases; Thin layer chromatography
- Publisher URL
- Copyright © 1980. Published by Elsevier B.V.
- Peer reviewed