FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2017188651> ?p ?o ?g. }

• W2017188651 endingPage "554" @default.
• W2017188651 startingPage "C" @default.
• W2017188651 abstract "Isolated reaction centers from Rhodopseudomonas viridis contain two high-potential c-type cytochromes, cytochrome c-559 and cytochrome c-556, and two low potential c-type cytochromes, cytochrome c-552 and cytochrome c-554. At moderate redox potentials, the two low-potential cytochromes are oxidized and are not identifiably involved in light-induced turnover. Following a flash, in the absence of functional secondary acceptor quinone, QB, the charge separation states, C+H2CH1Q−A and C+H2C+H1Q−A are rapidly created, where CH1 is cytochrome c-559 and CH2 is cytochrome c-556. Decay of these two states occurs via slow intramolecular charge recombinations. The rates of recombination for the two states were distinguishable and were pH and temperature dependent. At pH 9 and 296 K, kappH1 = 8.5 ± 0.5 s−1 for the charge recombination of C+H2C+H1Q−A and kappH2 = 0.95 ± 0.05 s−1 for the charge recombination of C+H2CH1Q−A. It was suggested that the mechanism for decay of both cytochrome c+Q−A states is via repopulation of the P+Q−A state, where P is the primary donor, followed by rapid (ms) recombination of this state, with a rate kP. Recovery of C+H2CH1Q−A also requires thermal equilibrium between the two hemes: C+H2CH1 a3 CH2C+H1. In addition to these indirect paths, there is a direct route of recovery for each of the states, C+H2CH1Q−A and C+H2C+H1Q−A. The direct pathways are evident at low temperature when the recovery processes become almost temperature independent, below about 220 K. In 60% ethylene glycol, the limiting rates are: k0H1 = 1.85 s− for C+H2C+H1Q−A, and k0H2 = 0.15 s−1 for C+H2CH1Q−A. That these rates differ by only a factor of 10 is remarkable in view of the 30 Å (center-to-center) separation between the two high-potential hemes and the involvement of intermediate states is briefly considered. From the model, the calculated rates, at any temperature, are given by: kappH1 = (kP + Kck0H1)(1 + Kc) for C+H2C+H1Q−A recombination, and kappH2 = [kP + Kc(k0H1 + Kek0H2)][1 + Kc(1 + Ke)] for C+H2CH1Q−A recombination, where Kc is the equilibrium constant for the positive hole to lie on either P or CH1, and Ke is the equilibrium constant for electron transfer between the two high-potential cytochromes, CH1 and CH2. Equilibrium redox titrations distinguished the two high-potential cytochromes c and revealed their distinct pH and temperature dependences. Kc was taken from the difference in the measured equilibrium midpoint potentials (ΔEm) of the C+H1/CH1 and P+/P couples, and Ke was taken from ΔEm for C+H2/CH2 and C+H1/CH1. The rate of P+Q−A decay, kP, was taken from measurements when all c-type cytochromes were chemically oxidized, and this was used to approximate the rate when the high-potential cytochromes were reduced. All three variable parameters were measured over a range of pH and temperature, and the calculated rates were compared to experimental rates determined under these conditions. The agreement between calculated and measured values was good and provides strong support for the proposed mechanism. The adequacy of equilibrium Em values and the measured value of kP is discussed in terms of possible electrostatic interactions between charged redox centers. It is concluded that such interactions are of minor importance for all relevant parameters in isolated reaction centers." @default.
• W2017188651 created "2016-06-24" @default.
• W2017188651 creator A5013853944 @default.
• W2017188651 creator A5074005623 @default.
• W2017188651 date "1984-01-01" @default.
• W2017188651 modified "2023-10-16" @default.
• W2017188651 title "De vogelaere's method with automatic error control" @default.
• W2017188651 cites W1525322792 @default.
• W2017188651 cites W1985494751 @default.
• W2017188651 cites W2028239295 @default.
• W2017188651 cites W2042668679 @default.
• W2017188651 cites W2053720845 @default.
• W2017188651 cites W2055123088 @default.
• W2017188651 cites W2062398106 @default.
• W2017188651 cites W2078826447 @default.
• W2017188651 cites W2092083503 @default.
• W2017188651 cites W2323178299 @default.
• W2017188651 cites W2324475288 @default.
• W2017188651 doi "https://doi.org/10.1016/s0010-4655(84)82729-0" @default.
• W2017188651 hasPublicationYear "1984" @default.
• W2017188651 type Work @default.
• W2017188651 sameAs 2017188651 @default.
• W2017188651 citedByCount "0" @default.
• W2017188651 crossrefType "journal-article" @default.
• W2017188651 hasAuthorship W2017188651A5013853944 @default.
• W2017188651 hasAuthorship W2017188651A5074005623 @default.
• W2017188651 hasConcept C104317684 @default.
• W2017188651 hasConcept C121332964 @default.
• W2017188651 hasConcept C156695909 @default.
• W2017188651 hasConcept C178790620 @default.
• W2017188651 hasConcept C181199279 @default.
• W2017188651 hasConcept C185592680 @default.
• W2017188651 hasConcept C188082385 @default.
• W2017188651 hasConcept C2780768313 @default.
• W2017188651 hasConcept C28859421 @default.
• W2017188651 hasConcept C29311851 @default.
• W2017188651 hasConcept C55493867 @default.
• W2017188651 hasConcept C55904794 @default.
• W2017188651 hasConcept C62520636 @default.
• W2017188651 hasConcept C71240020 @default.
• W2017188651 hasConcept C75079739 @default.
• W2017188651 hasConcept C75473681 @default.
• W2017188651 hasConcept C8010536 @default.
• W2017188651 hasConceptScore W2017188651C104317684 @default.
• W2017188651 hasConceptScore W2017188651C121332964 @default.
• W2017188651 hasConceptScore W2017188651C156695909 @default.
• W2017188651 hasConceptScore W2017188651C178790620 @default.
• W2017188651 hasConceptScore W2017188651C181199279 @default.
• W2017188651 hasConceptScore W2017188651C185592680 @default.
• W2017188651 hasConceptScore W2017188651C188082385 @default.
• W2017188651 hasConceptScore W2017188651C2780768313 @default.
• W2017188651 hasConceptScore W2017188651C28859421 @default.
• W2017188651 hasConceptScore W2017188651C29311851 @default.
• W2017188651 hasConceptScore W2017188651C55493867 @default.
• W2017188651 hasConceptScore W2017188651C55904794 @default.
• W2017188651 hasConceptScore W2017188651C62520636 @default.
• W2017188651 hasConceptScore W2017188651C71240020 @default.
• W2017188651 hasConceptScore W2017188651C75079739 @default.
• W2017188651 hasConceptScore W2017188651C75473681 @default.
• W2017188651 hasConceptScore W2017188651C8010536 @default.
• W2017188651 hasLocation W20171886511 @default.
• W2017188651 hasOpenAccess W2017188651 @default.
• W2017188651 hasPrimaryLocation W20171886511 @default.
• W2017188651 hasRelatedWork W1987978862 @default.
• W2017188651 hasRelatedWork W1993861701 @default.
• W2017188651 hasRelatedWork W1994926913 @default.
• W2017188651 hasRelatedWork W2017834455 @default.
• W2017188651 hasRelatedWork W2032788309 @default.
• W2017188651 hasRelatedWork W2038229599 @default.
• W2017188651 hasRelatedWork W2049468972 @default.
• W2017188651 hasRelatedWork W2605688738 @default.
• W2017188651 hasRelatedWork W2951639817 @default.
• W2017188651 hasRelatedWork W3196412968 @default.
• W2017188651 hasVolume "35" @default.
• W2017188651 isParatext "false" @default.
• W2017188651 isRetracted "false" @default.
• W2017188651 magId "2017188651" @default.
• W2017188651 workType "article" @default.