Interaction of F1-ATPase and its inhibitor peptide. Effect of dinitrophenol, nucleotides and anions.
1. ATPase natural inhibitor interacted in a mixed non-competitive manner with compounds affecting hydrolytic activity. 2. Ka's for DNP, HCO3- and free ATP, and Ki's for SCN- and ADP became smaller as inhibitor peptide concentration increased, reflecting an increase in affinity of F1-ATPase for these compounds induced by the peptide. 3. Activators increased the peptide inhibitory effect, whereas inhibitors decreased it. 4. A two-step model for the peptide-enzyme interaction is suggested in which ATP hydrolysis is a key factor.
de Miguel
C
C
Department of Biochemistry, University of Navarra, Pamplona, Spain.
Encío
I
I
López-Moratalla
N
N
Santiago
E
E
D019297:2,4-Dinitrophenol; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D000838:Anions / Q000494:pharmacology*; D001639:Bicarbonates / Q000494:pharmacology; D002417:Cattle; D004140:Dinitrophenols / Q000494:pharmacology*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology; D009711:Nucleotides / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D051381:Rats; D012966:Sodium Cyanide / Q000494:pharmacology; D000097795:ATPase Inhibitory Protein
D019297:2,4-Dinitrophenol; D000244:Adenosine Diphosphate; D000838:Anions; D001639:Bicarbonates; D004140:Dinitrophenols; D009711:Nucleotides; D011506:Proteins; D006180:Proton-Translocating ATPases; D012966:Sodium Cyanide; D000097795:ATPase Inhibitory Protein