Tran QM, Rothery RA, Maklashina E, Cecchini G, Weiner JH. The quinone binding site in Escherichia coli succinate dehydrogenase is required for electron transfer to the heme b. J Biol Chem. 2006 Oct 27;281(43):32310-7
2 comments:
Anonymous
said...
Very interesting. If a functional Q-site is required for heme b reduction, does Q depletion or adding Q-site inhibitors like AA5 block heme reduction? With substoichiometric Q or with excess Q and substoichiometric inhibitor, is there a fast phase of heme b reduction from those complexes with Q-loaded site, and slow phase mediated by Q transfer to complexes with blocked sites? i.e. is the inhibitor inhibiting reduction of the quinone or reduction of heme by the quinol (or both)?
Actually it was shown that pentachlorophenol reduces rate and extent of heme reduction. Maybe these experiments were done before atpenin became available?
2 comments:
Very interesting. If a functional Q-site is required for heme b reduction, does Q depletion or adding Q-site inhibitors like AA5 block heme reduction?
With substoichiometric Q or with excess Q and substoichiometric inhibitor, is there a fast phase of heme b reduction from those complexes with Q-loaded site, and slow phase mediated by Q transfer to complexes with blocked sites?
i.e. is the inhibitor inhibiting reduction of the quinone or reduction of heme by the quinol (or both)?
Actually it was shown that pentachlorophenol reduces rate and extent of heme reduction. Maybe these experiments were done before atpenin became available?
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