Similar affinities of ADP and ATP for G-actin at physiological salt concentrations.
The equilibrium constant for the exchange of ATP and ADP at G-actin was determined by fluorimetric titration of G-actin-bound epsilon-ATP by ATP or ADP. The affinity of ATP for G-actin was found to be only about 3-fold higher than the affinity of ADP for G-actin at 37 degrees C, pH 7.5 and physiologically relevant salt concentrations (100 mmol K+/l, 0.8 mmol Mg2+/l, less than 0.01 mmol Ca2+/l).
D000199:Actins / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D002122:Calcium Chloride; D008274:Magnesium; D015636:Magnesium Chloride; D009994:Osmolar Concentration; D011189:Potassium Chloride; D013050:Spectrometry, Fluorescence
D000199:Actins; D015636:Magnesium Chloride; D000244:Adenosine Diphosphate; D011189:Potassium Chloride; D000255:Adenosine Triphosphate; D008274:Magnesium; D002122:Calcium Chloride