Mitochondrial adenosine triphosphatase from human placenta--effects of adenylyl and guanylyl imidodiphosphate.
The effects of adenylylimidodiphosphate (AMP-PNP) and guanylylimidodiphosphate (GMP-PNP) on the kinetics of MgATP, MgITP and MgGTP hydrolysis by mitochondrial ATPase (EC 3.6.1.3) from human placenta were studied. AMP-PNP is a noncompetitive inhibitor of hydrolysis of all substrates used, both in the presence and in the absence of the activating HCO3- anion. At least two binding sites for AMP-PNP are present in the F1. Unlike AMP-PNP, GMP-PNP was shown to be a competitive inhibitor of hydrolysis of all substrates used. The results of the kinetic experiments presented support the alternating three-site mechanism of ATP hydrolysis by mitochondrial ATPase.
Aleksandrowicz
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D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives*; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology*; D001665:Binding Sites; D005260:Female; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011485:Protein Binding
D000266:Adenylyl Imidodiphosphate; D006165:Guanylyl Imidodiphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases