OLIGOMYCIN A

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.