title: [Method of measuring binding constants and the number of specific cyclic AMP receptor sites in tissue extracts].
abstract: A method for evaluation of binding constants and of amount of cAMP binding sites in crude tissue extracts was developed. The method is based on equilibrium binding of 3H-cAMP by proteins with subsequent ultrafiltration. Hydrolysis of cAMP and its unspecific sorption by proteins were eliminated under the conditions selected. Rat spleen cytosole contained 3.57 +/- 0.34 pmol of cAMP binding sites per mg of protein with dissociation constant of protein-cAMP complex (1.68 +/- 0.28).10(-8) M. As shown by studies on kinetics, binding constants and specificity of binding, the method permitted to evaluate quantitatively cAMP-dependent protein kinases in crude tissue extracts and to estimate their affinity to cAMP.
mesh_terms: D000818:Animals; D003600:Cytosol / Q000032:analysis; D066298:In Vitro Techniques; D008722:Methods; D051381:Rats; D011953:Receptors, Cyclic AMP / Q000032:analysis*; D013154:Spleen / Q000032:analysis
chemical_list: D011953:Receptors, Cyclic AMP
vernacular_title: Metod izmereniia konstant sviazyvaniia i kolichestva spetsificheskikh uchastkov retseptsii tsAMF v ékstraktakh tkani.