Affinity of Mg2+ for ATP (Kd)

Value 50 µM Range: ±10 µM
Organism Unspecified
Reference Bernstein BW, Bamburg JR. Actin-ATP hydrolysis is a major energy drain for neurons. J Neurosci. 2003 Jan 1 23(1):1-6. p.2 right column 2nd paragraphPubMed ID12514193
Primary Source Gupta RK, Gupta P, Yushok WD, Rose ZB (1983) Measurement of the dissociation constant of MgATP at physiological nucleotide levels by a combination of 31PNMRand optical absorbance spectroscopy. Biochem Biophys Res Commun 117: 210–216.PubMed ID6607050
Method (primary source abstract:)"The new combination method utilizes 31P NMR chemical shifts to determine the degree of Mg++ chelation of ATP in a solution containing free ATP and MgATP, and uses a properly calibrated indicator dye, antipyrylazo III, for optical measurement of free Mg++ in the same solution."
Comments "To monitor the loss of ATP in live cells, [researchers] took advantage of the fact that the affinity of Mg2+ for ATP (Kd=50±10µM) (primary source) is ~10-fold higher than for ADP or AMP (Leyssens et al., 1996). As ATP is hydrolyzed to ADP and AMP, [Mg2+]i rises (Budinger et al., 1998)."
Entered by Uri M
ID 110639