Comparison of (Ca2+-Mg2+)-ATPase and Ca2+-ATPase in rat cardiac sarcolemma.
The calcium dependency of the Ca2+-pump ATPase of rat cardiac sarcolemma was investigated in the presence and absence of EGTA and EDTA in combination with two free Mg2+-ion concentrations. The results showed: that Mg2+-ions are not essential for the turnover of the Ca2+-pump ATPase; that the Ca2+-affinity is regulated by the concentration of the calcium-chelator complex present in the medium; that (Ca2+-Mg2+)-ATPase and Ca2+-ATPase are probably expressions of the same Ca2+-pump ATPase in the plasma membrane of the cell.
Velema
J
J
Blom
J J
JJ
Zaagsma
J
J
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000032:analysis*; D002122:Calcium Chloride / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000032:analysis*; D004533:Egtazic Acid / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D009206:Myocardium / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D012508:Sarcolemma / Q000201:enzymology*
D004533:Egtazic Acid; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D002122:Calcium Chloride