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Nitroxide Spin-Labe...
Nitroxide Spin-Label Quenching of Fluorophore’s Triplet Stateas a Tool for Studying Diffusion Mediated Reactions in LipidMembranes
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- Strömqvist, Johan, 1976- (författare)
- KTH,Experimentell biomolekylär fysik
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- Chmyrov, Andriy, 1979- (författare)
- KTH,Experimentell biomolekylär fysik
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- Johansson, Sofia (författare)
- KTH,Experimentell biomolekylär fysik
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- Andersson, August (författare)
- Department of Biochemistry and Biophysics, Stockholm University
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- Mäler, Lena (författare)
- Department of Biochemistry and Biophysics, Stockholm University
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- Widengren, Jerker (författare)
- KTH,Experimentell biomolekylär fysik
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(creator_code:org_t)
- Engelska.
- Relaterad länk:
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https://kth.diva-por... (primary) (Raw object)
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https://urn.kb.se/re...
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Abstract
Ämnesord
Stäng
- In this work, we introduce an approach to study bimolecularinteractions in model lipid bilayers and biologicalmembranes, which exploits the influence of membrane-associatedElectron Spin Resonance (ESR) labels on the fluorescencesignal of likewise membrane-bound fluorophoremarkers. It is shown how one can exploit the high detectionsensitivity of the fluorescence signal without loosing the abilityto follow low-frequency molecular interactions, takingplace on a time scale well beyond that of the fluorescencelifetimes. The approach utilizes triplet state monitoring byFluorescence Correlation Spectroscopy (FCS), whereby thefluctuations in a strong fluorescence signal is used to characterizetransition rates to and from the lowest triplet stateof the fluorophores, which take place on a time scale 3 to 6orders of magnitude slower than the fluorescence lifetimesof the fluorophores. FCS measurements were performed onthe dye Lissamine Rhodamine B (LRB) in aqueous solutionsand bound to a lipid in a liposome, and in the presence of differentlocal concentrations of the ESR label TEMPO. Bothin the aqueous solution and in the lipid membrane measurements,the measured relative changes in the singlet-triplettransitions rates were found to well reflect the collisionalfrequencies between the LRB and TEMPO molecules. Theproposed approach, allowing low-frequency interactionsto be monitored with a bright fluorescence signal offers abroad applicability, both in terms of read-out means, typesof molecular interactions that can be followed, and in whatenvironment these interactions can be measured. From thispoint of view, it can prove useful for a broad category ofmolecular interaction studies.
Ämnesord
- NATURVETENSKAP -- Kemi -- Fysikalisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Physical Chemistry (hsv//eng)
Nyckelord
- Fluorescence correlation spectroscopy
- FCS
- triplet state
- TEMPO
- quenching
- diffusion
- membrane
- Spectroscopy
- Spektroskopi
Publikations- och innehållstyp
- pop (ämneskategori)
- ovr (ämneskategori)