[Mg(Ca)-ATPase of arterial muscle cells].
We could show an ATPase in mitochondrial and microsomal fractions of sheep arteria carotis communis and arteria coronaria of cattle which can be stimulated by Ca2+ of Mg2+, respectively. The enzyme has a higher affinity for Ca2+ than for Mg2+. The maximum activity of the Mg(Ca)-ATPase was found at 2-4 mM Ca2+ or Mg2+, respectively. Higher concentrations of these ions inhibit the enzyme. Mn2+, Sr2+ and Co2+ can substitute Ca2+ in splitting of ATP by the ATPase of both fractions of ateria coronaria of cattle. The ions K+ and Na+, variation of temperature and pH and a variety of pharmacological active compounds has the same effect on the ATPase stimulated by Ca2+ or Mg2+. These findings prove that Ca2+ and Mg2+ act at the same site of the ATPase of the mitochondrial and microsomal fraction of vascular smooth muscle.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001158:Arteries / Q000201:enzymology*; D002118:Calcium / Q000378:metabolism; D002339:Carotid Arteries / Q000201:enzymology; D002417:Cattle; D002458:Cell Fractionation; D003331:Coronary Vessels / Q000201:enzymology; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008861:Microsomes / Q000201:enzymology; D008931:Mitochondria, Muscle / Q000201:enzymology; D012756:Sheep
D000251:Adenosine Triphosphatases; D008274:Magnesium; D002118:Calcium
Mg(Ca)-ATPaza myshechnykh kletok arteriĭ.