[Reconstitution of sensitivity of solubilized rabbit heart adenylate cyclase to hormones and guanyl nucleotides].

Solubilization of adenylate cyclase by lubrol PX results in a loss of the enzyme sensitivity to hormones; however, the enzyme retains its ability to be activated by guanyl nucleotides and NaF. Lubrol WX devoids adenylate cyclase of its sensitivity to hormones and NaF. Solubilization causes a shift in the pH optimum of the enzyme towards neutral values of pH and significantly decreases the thermal stability of adenylate cyclase. The replacement of lubrol PX from the solubilized preparation by phospholipids increases the basal activity of adenylate cyclase (phosphatidyl serine) or restores its sensitivity to adrenaline and glucagon (phosphatidyl inositol). A reconstitution of the adenylate cyclase sensitivity to catecholamines by phosphatidyl inositol is also obtained after removal of the detergent excess using ion-exchange chromatography or lubrol PX replacement by cholate in the solubilized preparation. This restoration of the enzyme sensitivity to hormones is accompanied by an increase of the activating action of guanylylimidodiphosphate on the enzyme.