Improvement on the competitive binding assay for the measurement of cyclic AMP by using ammonium sulphate precipitation.
The protein-binding assay developed by Brown, Albano, Ekins, Sgherzi & Tampion [(1971) Biochem. J. 121, 561-562] and Brown, Ekins & Albano [(1972) Adv. Cyclic Nucleotide Res. 2, 25-40] was modified by using precipitation with (NH4)2SO4 of the protein-cyclic AMP complex instead of adsorption of the free nucleotide on charcoal. The half-life of the protein-cyclic AMP complex obtained in the presence of charcoal was lower than that of the (NH4)2SO4-precipitated complex. In consequence, owing to the great stability of the precipitated protein-cyclic AMP complex, this method allows more accurate and reproducible determinations.
Santa-Coloma
T A
TA
Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina.
Bley
M A
MA
Charreau
E H
EH
D000645:Ammonium Sulfate; D001667:Binding, Competitive; D011232:Chemical Precipitation; D000242:Cyclic AMP / Q000032:analysis*; D006207:Half-Life; D046911:Macromolecular Substances; D008722:Methods; D011485:Protein Binding
D046911:Macromolecular Substances; D000242:Cyclic AMP; D000645:Ammonium Sulfate