Amiloride inhibition of the proton-translocating NADH-quinone oxidoreductase of mammals and bacteria.
The proton-translocating NADH-quinone oxidoreductase in mitochondria (complex I) and bacteria (NDH-1) was shown to be inhibited by amiloride derivatives that are known as specific inhibitors for Na(+)/H(+) exchangers. In bovine submitochondrial particles, the effective concentrations were about the same as those for the Na(+)/H(+) exchangers, whereas in bacterial membranes the inhibitory potencies were lower. These results together with our earlier observation that the amiloride analogues prevent labeling of the ND5 subunit of complex I with a fenpyroximate analogue suggest the involvement of ND5 in H(+) (Na(+)) translocation and no direct involvement of electron carriers in H(+) (Na(+)) translocation.
Nakamaru-Ogiso
Eiko
E
Department of Molecular and Experimental Medicine, MEM-256, The Scripps Research Institute, 10550 Torrey Pines Road, La Jolla, CA 92037, USA.
Seo
Byoung Boo
BB
Yagi
Takao
T
Matsuno-Yagi
Akemi
A
D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology*; D000818:Animals; D001426:Bacterial Proteins; D002417:Cattle; D006801:Humans; D020128:Inhibitory Concentration 50; D007700:Kinetics; D024101:Mitochondrial Proteins; D009206:Myocardium / Q000201:enzymology; D021122:Protein Subunits / Q000037:antagonists & inhibitors*; D054328:Proton Pump Inhibitors; D011808:Quinone Reductases / Q000037:antagonists & inhibitors*
D001426:Bacterial Proteins; D024101:Mitochondrial Proteins; D021122:Protein Subunits; D054328:Proton Pump Inhibitors; D000584:Amiloride; C041831:NADH dehydrogenase (quinone); D011808:Quinone Reductases