[Properties of adenylate cyclase from plasma membranes of the rabbit myometrium in different functional states].
Adenylate cyclase of plasma membranes from the nonpregnant rabbit myometrium shows the maximum activity at pH 7.7-7.9, is characterized by apparent Km for ATP amounting to 0.38 +/- 0.09 mM, V--125 +/- 34.4 pmol min/mg protein, is activated at most by 15-20 mM Mg2+ and F-. Adenylate cyclase of plasma membranes from the pregnant rabbit myometrium is characterized by apparent Km for ATP amounting to 0.74 +/- 0.06 mM, V--77.3 +/- 6.0 pmol/min/mg protein, is activated at most by 5-10 mM Mg2+ and 10-15 mM F-; the pH optimum for the adenylate cyclase in this functional state is 7.3. Adenylate cyclase in the state of labour is characterized by apparent Km for ATP amounting to 0.46 +/- 0.11 mM, V--34.8 +/- 4.6 pmol/min/mg protein, is activated at most by 10-15 mM Mg2+ and F-, shows the same activity at pH 7.3-8.5. Adenylate cyclase of myometrium in three investigated states is activated by 2 mM EGTA; 10(-7) M Ca2+ decreases activation caused by EGTA; higher concentrations of Ca2+ decrease the basal activity of the enzyme.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D005260:Female; D007700:Kinetics; D009215:Myometrium / Q000201:enzymology*; D011247:Pregnancy / Q000378:metabolism*; D011817:Rabbits
D000262:Adenylyl Cyclases
Svoĭstva adenilattsiklazy plazmaticheskikh membran miometriia krol'chikhi pri razlichnykh funktsional'nykh sostoianiiakh.