Interactions of calcium and magnesium with the mitochondrial inorganic pyrophosphatase from Saccharomyces cerevisiae.
The activity of the mitochondrial inorganic pyrophosphatase from Saccharomyces cerevisiae was measured in the presence of increasing concentrations of magnesium and calcium. Calcium pyrophosphate (dissociation constant Kd = 1.9 microM) inhibited pyrophosphatase by competition with magnesium pyrophosphate (Kd = 50 microM). The small movements of calcium detected in mitochondria from yeast may be physiologically significant for the control of inorganic pyrophosphatase activity and the concentration of pyrophosphate in the matrix of yeast mitochondria.
Uribe
S
S
Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México.
Rangel
P
P
Pardo
J P
JP
Pereira-Da-Silva
L
L
D002118:Calcium / Q000378:metabolism*; D002131:Calcium Pyrophosphate / Q000494:pharmacology; D002458:Cell Fractionation; D011756:Diphosphates / Q000494:pharmacology; D043564:Inorganic Pyrophosphatase; D008274:Magnesium / Q000378:metabolism*; D017616:Magnesium Compounds / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology; D011755:Pyrophosphatases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D011756:Diphosphates; D017616:Magnesium Compounds; C034732:magnesium pyrophosphate; D011755:Pyrophosphatases; D043564:Inorganic Pyrophosphatase; D008274:Magnesium; D002118:Calcium; D002131:Calcium Pyrophosphate