Studies on the proton-translocating NADH:ubiquinone oxidoreductases of mitochondria and Escherichia coli using the inhibitor 1,10-phenanthroline.
Mitochondrial NADH:ubiquinone oxidoreductase (complex I) is uncompetitively inhibited by 1,10-phenanthroline (OP). EPR spectroscopy of submitochondrial particles indicates that OP, similarly to rotenone, inhibits electron transfer between the Fe-S clusters of complex I and the ubiquinone pool. The proton-translocating NADH dehydrogenase (NDH1) of E. coli is more sensitive to OP than is NDH1 of Paracoccus. EPR spectroscopy of membranous E. coli NDH1 shows that two slow- and one fast-relaxing Fe-S clusters become detectable upon reduction by NADH in the presence of OP. However, none of them resembles the mitochondrial cluster 2.
Finel
M
M
Helsinki Bioenergetics Group, Department of Medical Chemistry, University of Helsinki, Finland.
Majander
A
A
D000818:Animals; D002417:Cattle; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport / Q000187:drug effects; D042967:Electron Transport Complex I; D004926:Escherichia coli / Q000201:enzymology*; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D008929:Mitochondria, Heart / Q000201:enzymology; D008930:Mitochondria, Liver / Q000201:enzymology; D009243:NAD / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010618:Phenanthrolines / Q000494:pharmacology*; D011522:Protons; D051381:Rats; D013367:Submitochondrial Particles / Q000201:enzymology*
D007506:Iron-Sulfur Proteins; D010618:Phenanthrolines; D011522:Protons; D009243:NAD; D009247:NADH, NADPH Oxidoreductases; D042967:Electron Transport Complex I; C025205:1,10-phenanthroline