Binding domain of oligomycin on Na(+),K(+)-ATPase.
Oligomycin inhibits Na(+),K(+)-ATPase activity by stabilizing the Na(+) occlusion but not the K(+) occlusion. To locate the binding domain of oligomycin on Na(+),K(+)-ATPase, the tryptic-digestion profile of Na(+),K(+)-ATPase was compared with the profile of Na(+) occlusion within the digested Na(+),K(+)-ATPase in the presence of oligomycin. The Na(+) occlusion profile is responsible for the digestion profile of the alpha-subunit, which is the catalytic subunit of the ATPase. The effect of oligomycin on chimeric Ca(2+)-ATPase activity was examined. The chimera used, in which the 163 N-terminal amino acids of chicken sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase 1 were replaced with the 200 N-terminal amino acids of the chicken Na(+),K(+)-ATPase alpha1-subunit, partially retains the Na(+)-dependent characteristics of Na(+), K(+)-ATPase, because the chimeric Ca(2+)-ATPase activity is activated by Na(+) but inhibited by ouabain, a specific inhibitor of Na(+),K(+)-ATPase (Ishii, T., Lemas, M.V., Takeyasu, K., 1994, Proc. Natl. Acad. Sci. U. S. A., 91, 6103-6107). Oligomycin depressed the activation by Na(+) of the chimeric Ca(2+)-ATPase activity. These findings suggest that the 200 N-terminal amino acids of the Na(+), K(+)-ATPase alpha-subunit include a binding domain for oligomycin.
Homareda
H
H
First Department of Biochemistry, Kyorin University School of Medicine, Tokyo 181-8611, Mitaka, Japan. homareda@kyorin-u.ac.jp
Ishii
T
T
Takeyasu
K
K
D019943:Amino Acid Substitution; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D001665:Binding Sites; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D002645:Chickens; D004285:Dogs; D004791:Enzyme Inhibitors / Q000378:metabolism* / Q000494:pharmacology; D007739:L Cells; D051379:Mice; D009840:Oligomycins / Q000378:metabolism* / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D010446:Peptide Fragments / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013552:Swine; D019284:Thapsigargin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D009840:Oligomycins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D010042:Ouabain; D019284:Thapsigargin; D012964:Sodium; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase