Formation constants for the complexes of adenosine di- or tri-phosphate with magnesium or calcium ions
- 1 February 1959
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 71 (2), 388-395
- https://doi.org/10.1042/bj0710388
Abstract
The formation of complexes between adenosine tri- or di-phosphate (ATP or ADP) and Mg++ or Ca++ has been studied in aqueous solution at pH 7.9-8.9. A spectrophotometric method was used in which 8-hydroxyquinoline acts as an indicator of free metal ion. Adenosine triphosphate has a much greater affinity for both metals than has adenosine diphosphate. The formation constants (i.e. reciprocals of the dissociation constants) for the MgATP[long dash]and MgADP[long dash]complexes were 38,000 and 2200[image] -1 respectively at 25[degree], or 98,000 and 6900[image] -1 at 64[degree] (I 0.11; 85 m[image] tributylethylammonium bromide plus 25 m[image] triethanolamine hydrochloride). The interpolated values for 37[degree] are 55,000 and 3300[image] -1 respectively. There was no clear indication that bimetallic complexes were formed at concentrations of up to 80 m[image] Mg++ or Ca++. The results also indicate the formation of a ternary complex between Mg, ATP and 8-hydroxyquinoline.Keywords
This publication has 12 references indexed in Scilit:
- Energy of Adenosine TriphosphateNature, 1958
- THE ROLE OF COMPLEX METAL IONS IN THE YEAST HEXOKINASE REACTIONJournal of Biological Chemistry, 1958
- [Nucleotides of adenine. IV. Instability of magnesium complexes of adenosinetriphosphate].1958
- DETERMINATION OF THE EQUILIBRIUM OF THE HEXOKINASE REACTION AND THE FREE ENERGY OF HYDROLYSIS OF ADENOSINE TRIPHOSPHATEJournal of Biological Chemistry, 1957
- Ultraviolet absorption spectra of adenosine-5′-triphosphate and related 5′-ribonucleotidesArchives of Biochemistry and Biophysics, 1956
- [Metal buffer function of adenosinephosphates].1956
- SODIUM AND POTASSIUM COMPLEXES OF ADENOSINE-TRIPHOSPHATE: EQUILIBRIUM STUDIESJournal of Biological Chemistry, 1954
- Some reactions of adenosine and inosine phosphates in animal tissuesBiochimica et Biophysica Acta, 1953
- The free-energy changes associated with the individual steps of the tricarboxylic acid cycle, glycolysis and alcoholic fermentation and with the hydrolysis of the pyrophosphate groups of adenosinetriphosphateBiochemical Journal, 1953
- CALCIUM COMPLEXES OF ADENOSINETRIPHOSPHATE AND ADENOSINEDIPHOSPHATE AND THEIR SIGNIFICANCE IN CALCIFICATION INVITRO1953