Publikation: Electrogenic partial reactions of the SR-Ca-ATPase investigated by a fluorescence method
Dateien
Datum
Autor:innen
Herausgeber:innen
ISSN der Zeitschrift
Electronic ISSN
ISBN
Bibliografische Daten
Verlag
Schriftenreihe
Auflagebezeichnung
URI (zitierfähiger Link)
DOI (zitierfähiger Link)
Internationale Patentnummer
Link zur Lizenz
Angaben zur Forschungsförderung
Projekt
Open Access-Veröffentlichung
Sammlungen
Core Facility der Universität Konstanz
Titel in einer weiteren Sprache
Publikationstyp
Publikationsstatus
Erschienen in
Zusammenfassung
A fluorescence method was adapted to investigate active ion transport in membrane preparations of the SR-Ca-ATPase. The styryl dye RH421 previously used to investigate the Na,K-ATPase was replaced by an analogue, 2BITC, to obtain optimized fluorescence changes upon substrate-induced partial reactions. Assuming changes of the local electric field to be the source of fluorescence changes that are produced by uptake/release or by movement of ions inside the protein, 2BITC allowed the determination of electrogenic partial reactions in the pump cycle. It was found that Ca2+ binding on the cytoplasmic and on the lumenal side of the pump is electrogenic while phosphorylation and conformational transition showed only minor electrogenicity. Ca2+ equilibrium titration experiments at pH 7.2 in the two major conformations of the protein indicated cooperative binding of two Ca2+ ions in state E1 with an apparent half-saturation concentration, KM of 600 nm. In state P-E2 two KM values, 5 μm and 2.2 mM, were determined and are in fair agreement with published data. From Ca2+ titrations in buffers with various pH and from pH titrations in P-E2, it could be demonstrated that H+ binding is electrogenic and that Ca2+ and H+ compete for the same binding site(s). Tharpsigargin-induced inhibition of the Ca-ATPase led to a state with a specific fluorescence level comparable to that of state E1 with unoccupied ion sites, independent of the buffer composition.
Zusammenfassung in einer weiteren Sprache
Fachgebiet (DDC)
Schlagwörter
Konferenz
Rezension
Zitieren
ISO 690
BUTSCHER, Christine, Milena ROUDNA, Hans-Jürgen APELL, 1999. Electrogenic partial reactions of the SR-Ca-ATPase investigated by a fluorescence method. In: Journal of Membrane Biology. 1999, 168(2), pp. 169-181. ISSN 0022-2631. eISSN 1432-1424. Available under: doi: 10.1007/s002329900507BibTex
@article{Butscher1999Elect-6520, year={1999}, doi={10.1007/s002329900507}, title={Electrogenic partial reactions of the SR-Ca-ATPase investigated by a fluorescence method}, number={2}, volume={168}, issn={0022-2631}, journal={Journal of Membrane Biology}, pages={169--181}, author={Butscher, Christine and Roudna, Milena and Apell, Hans-Jürgen} }
RDF
<rdf:RDF xmlns:dcterms="http://purl.org/dc/terms/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:bibo="http://purl.org/ontology/bibo/" xmlns:dspace="http://digital-repositories.org/ontologies/dspace/0.1.0#" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:void="http://rdfs.org/ns/void#" xmlns:xsd="http://www.w3.org/2001/XMLSchema#" > <rdf:Description rdf:about="https://kops.uni-konstanz.de/server/rdf/resource/123456789/6520"> <dcterms:bibliographicCitation>First publ. in: Journal of Membrane Biology 168 (1999), pp. 169-181</dcterms:bibliographicCitation> <dcterms:available rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2011-03-24T17:26:44Z</dcterms:available> <dspace:hasBitstream rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/6520/1/Electrogenic_partial_reactions_of_the.pdf"/> <dc:contributor>Butscher, Christine</dc:contributor> <bibo:uri rdf:resource="http://kops.uni-konstanz.de/handle/123456789/6520"/> <dc:contributor>Apell, Hans-Jürgen</dc:contributor> <foaf:homepage rdf:resource="http://localhost:8080/"/> <dcterms:issued>1999</dcterms:issued> <dcterms:abstract xml:lang="eng">A fluorescence method was adapted to investigate active ion transport in membrane preparations of the SR-Ca-ATPase. The styryl dye RH421 previously used to investigate the Na,K-ATPase was replaced by an analogue, 2BITC, to obtain optimized fluorescence changes upon substrate-induced partial reactions. Assuming changes of the local electric field to be the source of fluorescence changes that are produced by uptake/release or by movement of ions inside the protein, 2BITC allowed the determination of electrogenic partial reactions in the pump cycle. It was found that Ca2+ binding on the cytoplasmic and on the lumenal side of the pump is electrogenic while phosphorylation and conformational transition showed only minor electrogenicity. Ca2+ equilibrium titration experiments at pH 7.2 in the two major conformations of the protein indicated cooperative binding of two Ca2+ ions in state E1 with an apparent half-saturation concentration, KM of 600 nm. In state P-E2 two KM values, 5 μm and 2.2 mM, were determined and are in fair agreement with published data. From Ca2+ titrations in buffers with various pH and from pH titrations in P-E2, it could be demonstrated that H+ binding is electrogenic and that Ca2+ and H+ compete for the same binding site(s). Tharpsigargin-induced inhibition of the Ca-ATPase led to a state with a specific fluorescence level comparable to that of state E1 with unoccupied ion sites, independent of the buffer composition.</dcterms:abstract> <dc:creator>Butscher, Christine</dc:creator> <dc:creator>Apell, Hans-Jürgen</dc:creator> <dcterms:hasPart rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/6520/1/Electrogenic_partial_reactions_of_the.pdf"/> <dcterms:rights rdf:resource="http://creativecommons.org/licenses/by-nc-nd/2.0/"/> <dspace:isPartOfCollection rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/28"/> <dcterms:isPartOf rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/28"/> <dcterms:title>Electrogenic partial reactions of the SR-Ca-ATPase investigated by a fluorescence method</dcterms:title> <dc:contributor>Roudna, Milena</dc:contributor> <dc:rights>Attribution-NonCommercial-NoDerivs 2.0 Generic</dc:rights> <dc:date rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2011-03-24T17:26:44Z</dc:date> <dc:language>eng</dc:language> <dc:creator>Roudna, Milena</dc:creator> <dc:format>application/pdf</dc:format> <void:sparqlEndpoint rdf:resource="http://localhost/fuseki/dspace/sparql"/> </rdf:Description> </rdf:RDF>