dc.contributor.author
Volz, Pierre
dc.contributor.author
Krause, Nils
dc.contributor.author
Balke, Jens
dc.contributor.author
Schneider, Constantin
dc.contributor.author
Walter, Maria
dc.contributor.author
Schneider, Franziska
dc.contributor.author
Schlesinger, Ramona
dc.contributor.author
Alexiev, Ulrike
dc.date.accessioned
2017-08-01
dc.date.available
2017-08-02T08:35:19.002Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/21017
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-24314
dc.description.abstract
A variant of the cation channel channelrhodopsin-2 from Chlamydomonas
reinhardtii (CrChR2) was selectively labeled at position Cys-79 at the end of
the first cytoplasmic loop and the beginning of transmembrane helix B with the
fluorescent dye fluorescein (acetamidofluorescein). We utilized (i) time-
resolved fluorescence anisotropy experiments to monitor the structural
dynamics at the cytoplasmic surface close to the inner gate in the dark and
after illumination in the open channel state and (ii) time-resolved
fluorescence quenching experiments to observe the solvent accessibility of
helix B at pH 6.0 and 7.4. The light-induced increase in final anisotropy for
acetamidofluorescein bound to the channel variant with a prolonged conducting
state clearly shows that the formation of the open channel state is associated
with a large conformational change at the cytoplasmic surface, consistent with
an outward tilt of helix B. Furthermore, results from solute accessibility
studies of the cytoplasmic end of helix B suggest a pH-dependent structural
heterogeneity that appears below pH 7. At pH 7.4 conformational homogeneity
was observed, whereas at pH 6.0 two protein fractions exist, including one in
which residue 79 is buried. This inaccessible fraction amounts to 66% in
nanodiscs and 82% in micelles. Knowledge about pH-dependent structural
heterogeneity may be important for CrChR2 applications in optogenetics.
en
dc.format.extent
13 Seiten
dc.rights.uri
http://www.jbc.org/site/misc/Copyright_Permission.xhtml
dc.subject
fluorescence anisotropy
dc.subject
membrane protein
dc.subject
protein conformation
dc.subject
channelrhodopsin
dc.subject
fluorescence quenching
dc.subject.ddc
500 Naturwissenschaften und Mathematik::530 Physik
dc.title
Light and pH-induced Changes in Structure and Accessibility of Transmembrane
Helix B and Its Immediate Environment in Channelrhodopsin-2
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation
This research was originally published in The Journal of Biological Chemistry.
Pierre Volz, Nils Krause, Jens Balke, Constantin Schneider, Maria Walter,
Franziska Schneider, Ramona Schlesinger and Ulrike Alexiev. Light and pH-
induced Changes in Structure and Accessibility of Transmembrane Helix B and
Its Immediate Environment in Channelrhodopsin-2. The Journal of Biological
Chemistry. 2016; 291:17382-17393. © the American Society for Biochemistry and
Molecular Biology
dc.identifier.sepid
54986
dcterms.bibliographicCitation.doi
10.1074/jbc.M115.711200
dcterms.bibliographicCitation.url
http://dx.doi.org/10.1074/jbc.M115.711200
refubium.affiliation
Physik
de
refubium.affiliation.other
Institut für Experimentalphysik
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refubium.mycore.fudocsId
FUDOCS_document_000000026396
refubium.resourceType.isindependentpub
no
refubium.mycore.derivateId
FUDOCS_derivate_000000008599
dcterms.accessRights.openaire
open access
dcterms.isPartOf.issn
0021-9258