The interaction of nucleotides with F1-ATPase inactivated with 4-chloro-7-nitrobenzofurazan.
In common with the F1-ATPase from other sources, yeast mitochondrial F1-ATPase was inhibited by 4-chloro-7-nitrobenzofurazan. Total inhibition of the F1-ATPase activity was compatible with the modification of a single tyrosine residue per F1-ATPase molecule. Radioactive labelling experiments localized this modification on a beta-subunit. The inactive modified enzyme retained the capacity to bind the photoaffinity label 8-azido-1,N6-etheno-ATP, which has previously been shown to bind nucleotide sites of low affinity. As well, the inactive modified enzyme bound MgATP with high affinity, yielding a Kd of 14 microM. The results are consistent with the hypothesis of alternating, or cooperative, site catalysis by F1-ATPase.
D009327:4-Chloro-7-nitrobenzofurazan / Q000494:pharmacology*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives*; D000345:Affinity Labels / Q000494:pharmacology*; D001386:Azides; D001665:Binding Sites; D004985:Ethenoadenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D007700:Kinetics; D010069:Oxadiazoles / Q000494:pharmacology*; D010085:Oxidative Phosphorylation; D011485:Protein Binding; D006180:Proton-Translocating ATPases; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
C016253:8-azido-1,N(6)-ethenoadenosine triphosphate; D000345:Affinity Labels; D001386:Azides; D004985:Ethenoadenosine Triphosphate; D010069:Oxadiazoles; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D006180:Proton-Translocating ATPases; D009327:4-Chloro-7-nitrobenzofurazan