Evidence for protein dielectric relaxations in reaction centers associated with the primary charge separation detected from Rhodospirillum rubrum chromatophores by combined photovoltage and absorption measurements in the 1-15 ns time range

DC FieldValueLanguage
dc.contributor.authorTrissl, HW
dc.contributor.authorBernhardt, K
dc.contributor.authorLapin, M
dc.date.accessioned2021-12-23T16:02:28Z-
dc.date.available2021-12-23T16:02:28Z-
dc.date.issued2001
dc.identifier.issn00062960
dc.identifier.urihttps://osnascholar.ub.uni-osnabrueck.de/handle/unios/5429-
dc.description.abstractFast photovoltage measurements in Rhodospirillum rubrum chromatophores in the nanosecond time range, escorted by time-resolved absorption measurements, are described. Under reducing conditions, the photovoltage decayed significantly faster than the spectroscopically detected charge recombination of the radical pair P+HA-. This indicates the occurrence of considerable dielectric relaxations. Our data and data from the literature were analyzed by means of a reaction scheme consisting of three states, namely, A*, P* and P(+)HA(-). A time-dependent DeltaG(t) was introduced by assuming a time-dependent rate constant of the back-reaction, k(-1)(t). With the exception of the latter rate constant, all ether parameters of the model are reliably known within narrow limits. This allowed us to distinguish between the three cases assumed for DeltaG degrees (t): (1)DeltaG degrees (t) = constant; (2)DeltaG degrees (t) as published by Peloquin et al. [Peloquin, J. M., Williams, J. C., Lin, X. M., Alden, R. G., Taguchi, A. K. W., Allen, J. P., and Woodbury, N. W. (1994) Biochemistry 33, 8089-8100]; and a (3)DeltaG degrees (t) that fits the present data. The assumption that (1)DeltaG degrees (t) = constant is incompatible with our photovoltage data, and (2)DeltaG degrees (t) is incompatible with the constraint that the ratio of fluorescence yields in the closed and open state is F-m/F-o approximate to 2. We specify a (3)DeltaG degrees (t) that should be valid for photosynthetic reaction centers in vivo. Furthermore, the overall kinetics of the electric relaxation, e(t), in response to the primary charge separation were determined.
dc.language.isoen
dc.publisherAMER CHEMICAL SOC
dc.relation.ispartofBIOCHEMISTRY
dc.subjectBACTERIAL REACTION CENTERS
dc.subjectBACTERIORHODOPSIN
dc.subjectBiochemistry & Molecular Biology
dc.subjectCLOSED PHOTOSYSTEM-II
dc.subjectCONFORMATIONAL-CHANGES
dc.subjectELECTRON-TRANSFER KINETICS
dc.subjectFLUORESCENCE
dc.subjectPHOTOSYNTHETIC REACTION CENTERS
dc.subjectRHODOBACTER-SPHAEROIDES
dc.subjectRHODOPSEUDOMONAS-SPHAEROIDES
dc.subjectVOLUME CHANGES
dc.titleEvidence for protein dielectric relaxations in reaction centers associated with the primary charge separation detected from Rhodospirillum rubrum chromatophores by combined photovoltage and absorption measurements in the 1-15 ns time range
dc.typejournal article
dc.identifier.doi10.1021/bi001885u
dc.identifier.isiISI:000168435100022
dc.description.volume40
dc.description.issue17
dc.description.startpage5290
dc.description.endpage5298
dc.contributor.orcid0000-0002-3557-929X
dc.contributor.researcheridG-6507-2017
dc.publisher.place1155 16TH ST, NW, WASHINGTON, DC 20036 USA
dcterms.isPartOf.abbreviationBiochemistry
crisitem.author.deptFB 05 - Biologie/Chemie-
crisitem.author.deptidfb05-
crisitem.author.orcid0000-0002-7716-587X-
crisitem.author.parentorgUniversität Osnabrück-
crisitem.author.netidBeKa535-
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