Enzyme inhibitor
These macrolide antibiotics from Streptomyces diastatochromogenes have
three major members: Oligomycin A (FW = 791.08 g/mol; CAS 14104-19-
9), Oligomycin B (FW = 805.06 g/mol; CAS 11050-94-5), and Oligomycin
C (FW = 775.08 g/mol; CAS 11052-72-5). Others include Oligomycin D
(also known as rutamycin; FW = 777.05 g/mol; CAS 1404-59-7),
Rutamycin B (isolated from Streptomyces aureofaciens (See also
Rutamycin) ), and Oligomycin E (FW = 822.07 g/mol; CAS 110231-34-0;
isolated from Streptomyces sp. MCI-2225). Primary Mode of Inhibitory
Action: The oligomycins inhibit the ATP synthesis activity of the
mitochondrial FoF1 ATP synthase, defining the “o” (not 0) in the first
subscript. The ATPase activity of the isolated F1 complex is unaffected by
oligomycins, unlike the Fo portion. Oligomycin-sensitivity conferring
ptrotein (OSCP) interacts with other components in the ATP synthase
complex and facilitates oligomycin’s binding to the Fo unit. The Fo complex
is, in fact, an integral membrane protein that functions as a proton channel.
Other Actions: Oligomycins also inhibit Na+/K+-exchanging ATPases that
transport sodium ions from the inside to the outside of animal cells while
translocating potassium ions in the reverse direction with the concomitant
hydrolysis of ATP. Oligomycin inhibits Na+ translocation in vivo (i.e., the
enzyme activity is inhibited by stabilizing the Na occlusion but not the K
occlusion). Other Properties: The oligomycins are slightly soluble in water
(e.g., oligomycin A has a solubility of 2 μg per 100 mL at 25°C) and are
considerable more soluble in water-miscible solvents such as ethanol,
acetone, and glacial acetic acid. Target (s) : aldehyde oxidase; ammonia
kinase; apyrase, membrane-bound; ATP synthase, or FoF1 ATP
synthas; calcidiol 1-monooxygenase; copper-exporting
ATPase, partially inhibited; endopeptidase La, weakly inhibited;
H+-transporting ATPase, lysosomal; Na+/K+-exchanging ATPase (24-
32); nucleoside triphosphatase; photophosphorylation in
Rhodospirillum rubrum; xenobiotic-transporting ATPases.
