[Properties of adenylate cyclase of plasma membrane from the rabbit myometrium].

Some kinetic properties of adenylate cyclase of plasma membrane myometrium were studied in nonpregnant rabbit. The apparent Km for ATP and V were 0.38 mM and 125 pmol cAMP/mg protein/min, respectively. The maximal activity of enzyme was observed at the Mg2+ concentration of about 15-20 mM and pH 7.7-7.9. Adenylate cyclase possessed sensitivity for F-, the maximal stimulation was observed at the F- concentration of 15 mM. 2 mM EGTA, 10(-8) M Ca2+ activated the enzyme. Argumentation of the Ca2+ concentration from 10(-7) to 10(-3) M led to adenylate cyclase inhibition.