Matches in SemOpenAlex for { <https://semopenalex.org/work/W2105402562> ?p ?o ?g. }
- W2105402562 endingPage "7874" @default.
- W2105402562 startingPage "7866" @default.
- W2105402562 abstract "The cytochrome (cyt) bc(1) complex is central to energy transduction in many species. Most investigators now accept a modified Q-cycle as the catalytic mechanism of this enzyme. Several thermodynamically favorable side reactions must be minimized for efficient functioning of the Q-cycle. Among these, reduction of oxygen by the Q(o) site semiquinone to produce superoxide is of special pathobiological interest. These superoxide-producing bypass reactions are most notably observed as the antimycin A- or myxothiazol-resistant reduction of cyt c. In this work, we demonstrate that these inhibitor-resistant cyt c reductase activities are largely unaffected by removal of O(2) in the isolated yeast cyt bc(1) complex. Further, increasing O(2) tension 5-fold stimulated the antimycin A-resistant reduction by a small amount ( approximately 25%), while leaving the myxothiazol-resistant reduction unchanged. This most likely indicates that the rate-limiting step in superoxide production is the formation of a reactive species (probably a semiquinone), capable of rapid O(2) reduction, and that in the absence of O(2) this species can reduce cyt c by some other pathway. We suggest as one possibility that a semiquinone escapes from the Q(o) site and reduces either O(2) or cyt c directly. The small increase in antimycin A-resistant cyt c reduction rate at high O(2) can be explained by the accumulation of a low concentration of a semiquinone inside the Q(o) site. Under aerobic conditions, addition of saturating levels of superoxide dismutase (SOD) inhibited 50% of cyt c reduction in the presence of myxothiazol, implying that essentially all bypass reactions occur with the production of superoxide. However, SOD inhibited only 35% of antimycin A-resistant cyt c reduction, suggesting the presence of a second, slower bypass reaction that does not reduce O(2). Given that myxothiazol blocks cyt b reduction whereas antimycin A promotes it, we propose that this second bypass occurs by reduction of the Q(o) site semiquinone by prereduced cyt b(L)." @default.
- W2105402562 created "2016-06-24" @default.
- W2105402562 creator A5021772801 @default.
- W2105402562 creator A5056873512 @default.
- W2105402562 creator A5062055196 @default.
- W2105402562 date "2002-05-25" @default.
- W2105402562 modified "2023-10-16" @default.
- W2105402562 title "Multiple Q-Cycle Bypass Reactions at the Q<sub>o</sub> Site of the Cytochrome <i>bc</i><sub>1</sub> Complex" @default.
- W2105402562 cites W1481883899 @default.
- W2105402562 cites W1495002664 @default.
- W2105402562 cites W1506060840 @default.
- W2105402562 cites W1533330634 @default.
- W2105402562 cites W1541928539 @default.
- W2105402562 cites W1563623183 @default.
- W2105402562 cites W1576822037 @default.
- W2105402562 cites W1872820540 @default.
- W2105402562 cites W1911339081 @default.
- W2105402562 cites W1982387375 @default.
- W2105402562 cites W1987981231 @default.
- W2105402562 cites W2005381951 @default.
- W2105402562 cites W2013805538 @default.
- W2105402562 cites W2016942442 @default.
- W2105402562 cites W2048484224 @default.
- W2105402562 cites W2051913989 @default.
- W2105402562 cites W2063451918 @default.
- W2105402562 cites W2072570851 @default.
- W2105402562 cites W2092763583 @default.
- W2105402562 cites W2095898657 @default.
- W2105402562 cites W2103604301 @default.
- W2105402562 cites W2104633154 @default.
- W2105402562 cites W2113007696 @default.
- W2105402562 cites W2132826785 @default.
- W2105402562 cites W2162156855 @default.
- W2105402562 cites W2170621128 @default.
- W2105402562 cites W2253514935 @default.
- W2105402562 cites W307329154 @default.
- W2105402562 doi "https://doi.org/10.1021/bi025581e" @default.
- W2105402562 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/12069575" @default.
- W2105402562 hasPublicationYear "2002" @default.
- W2105402562 type Work @default.
- W2105402562 sameAs 2105402562 @default.
- W2105402562 citedByCount "153" @default.
- W2105402562 countsByYear W21054025622012 @default.
- W2105402562 countsByYear W21054025622013 @default.
- W2105402562 countsByYear W21054025622014 @default.
- W2105402562 countsByYear W21054025622015 @default.
- W2105402562 countsByYear W21054025622016 @default.
- W2105402562 countsByYear W21054025622017 @default.
- W2105402562 countsByYear W21054025622018 @default.
- W2105402562 countsByYear W21054025622019 @default.
- W2105402562 countsByYear W21054025622020 @default.
- W2105402562 countsByYear W21054025622021 @default.
- W2105402562 countsByYear W21054025622022 @default.
- W2105402562 countsByYear W21054025622023 @default.
- W2105402562 crossrefType "journal-article" @default.
- W2105402562 hasAuthorship W2105402562A5021772801 @default.
- W2105402562 hasAuthorship W2105402562A5056873512 @default.
- W2105402562 hasAuthorship W2105402562A5062055196 @default.
- W2105402562 hasConcept C134651460 @default.
- W2105402562 hasConcept C14471203 @default.
- W2105402562 hasConcept C181199279 @default.
- W2105402562 hasConcept C185592680 @default.
- W2105402562 hasConcept C2775838275 @default.
- W2105402562 hasConcept C2776370595 @default.
- W2105402562 hasConcept C2779965811 @default.
- W2105402562 hasConcept C2780643102 @default.
- W2105402562 hasConcept C2780768313 @default.
- W2105402562 hasConcept C2780795997 @default.
- W2105402562 hasConcept C28859421 @default.
- W2105402562 hasConcept C29311851 @default.
- W2105402562 hasConcept C48349386 @default.
- W2105402562 hasConcept C55493867 @default.
- W2105402562 hasConcept C63338738 @default.
- W2105402562 hasConcept C71240020 @default.
- W2105402562 hasConcept C75473681 @default.
- W2105402562 hasConceptScore W2105402562C134651460 @default.
- W2105402562 hasConceptScore W2105402562C14471203 @default.
- W2105402562 hasConceptScore W2105402562C181199279 @default.
- W2105402562 hasConceptScore W2105402562C185592680 @default.
- W2105402562 hasConceptScore W2105402562C2775838275 @default.
- W2105402562 hasConceptScore W2105402562C2776370595 @default.
- W2105402562 hasConceptScore W2105402562C2779965811 @default.
- W2105402562 hasConceptScore W2105402562C2780643102 @default.
- W2105402562 hasConceptScore W2105402562C2780768313 @default.
- W2105402562 hasConceptScore W2105402562C2780795997 @default.
- W2105402562 hasConceptScore W2105402562C28859421 @default.
- W2105402562 hasConceptScore W2105402562C29311851 @default.
- W2105402562 hasConceptScore W2105402562C48349386 @default.
- W2105402562 hasConceptScore W2105402562C55493867 @default.
- W2105402562 hasConceptScore W2105402562C63338738 @default.
- W2105402562 hasConceptScore W2105402562C71240020 @default.
- W2105402562 hasConceptScore W2105402562C75473681 @default.
- W2105402562 hasIssue "25" @default.
- W2105402562 hasLocation W21054025621 @default.
- W2105402562 hasLocation W21054025622 @default.
- W2105402562 hasOpenAccess W2105402562 @default.
- W2105402562 hasPrimaryLocation W21054025621 @default.
- W2105402562 hasRelatedWork W1494531967 @default.