TY - GEN A1 - Wessig, Pablo A1 - Hille, Carsten A1 - Kumke, Michael Uwe A1 - Meiling, Till Thomas A1 - Behrends, Nicole A1 - Eisold, Ursula T1 - Two-photon FRET pairs based on coumarin and DBD dyes N2 - The synthesis and photophysical properties of two new FRET pairs based on coumarin as a donor and DBD dye as an acceptor are described. The introduction of a bromo atom dramatically increases the two-photon excitation (2PE) cross section providing a 2PE-FRET system, which is also suitable for 2PE-FLIM. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 318 KW - resonance energy-tansfer KW - conformational-changes KW - microscopy KW - proteins KW - acid Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394445 SP - 33510 EP - 33513 ER - TY - JOUR A1 - Wessig, Pablo A1 - Behrends, Nicole A1 - Kumke, Michael Uwe A1 - Eisold, Ursula A1 - Meiling, Til A1 - Hille, Carsten T1 - Two-photon FRET pairs based on coumarin and DBD dyes JF - RSC Advances N2 - The synthesis and photophysical properties of two new FRET pairs based on coumarin as a donor and DBD dye as an acceptor are described. The introduction of a bromo atom dramatically increases the two-photon excitation (2PE) cross section providing a 2PE-FRET system, which is also suitable for 2PE-FLIM. Y1 - 2016 U6 - https://doi.org/10.1039/c6ra03983a SN - 2046-2069 VL - 6 SP - 33510 EP - 33513 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Wessig, Pablo A1 - Behrends, Nicole A1 - Kumke, Michael Uwe A1 - Eisold, Ursula T1 - FRET Pairs with Fixed Relative Orientation of Chromophores JF - European journal of organic chemistry N2 - Synthetic routes to different oligospirothioketal (OSTK) Forster resonance energy transfer (FRET) constructs are described and the photophysics of these constructs were explored in different solvents. The FRET efficiencies were determined from the experimental data and compared with theoretical values. The influence of the outstanding rigidity of the novel OSTK compounds on the FRET is discussed. KW - Fluorescence KW - Energy transfer KW - FRET KW - Chromophores KW - Spiro compounds Y1 - 2016 U6 - https://doi.org/10.1002/ejoc.201600489 SN - 1434-193X SN - 1099-0690 VL - 145 SP - 4476 EP - 4486 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Eisold, Ursula A1 - Behrends, Nicole A1 - Wessig, Pablo A1 - Kumke, Michael Uwe T1 - Rigid Rod-Based FRET Probes for Membrane Sensing Applications JF - The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces & biophysical chemistry N2 - Oligospirothioketal (OSTK) rods are presented as an adjustable scaffold for optical membrane probes. The OSTK rods are readily incorporated into lipid bilayers due to their hydrophobic backbones. Because of their high length-over-diameter aspect ratio, only a minimal disturbance of the lipid bilayer is caused. OSTK rods show outstanding rigidity and allow defined labeling with fluorescent dyes, yielding full control of the orientation between the dye and OSTK skeleton. This. allows the construction of novel Forster resonance energy transfer probes with highly defined relative orientations of the transition dipole moments of the donor and acceptor dyes and makes the class of OSTK probes a power-fill, flexible toolbox for optical biosensing applications. Data on steady-state and time-resolved fluorescence experiments investigating the incorporation of coumarin- and [1,3]-dioxolo[4,5-f][1,3]benzo-dioxole-labeled OSTKs in large unilamellar vesicles are presented as a show case. Y1 - 2016 U6 - https://doi.org/10.1021/acs.jpcb.6b07285 SN - 1520-6106 VL - 120 SP - 9935 EP - 9943 PB - American Chemical Society CY - Washington ER - TY - THES A1 - Behrends, Nicole T1 - Funktionalisierte OS(T)K-Stäbe und Sensorfluorophore zur optischen Sensorik T1 - Functionalized OS(T)K-rods and dyes for optical sensor systems N2 - Im Rahmen dieser Arbeit wurden zum einen erste Oligospiro(thio)ketal (OS(T)K)-basierte Modellsysteme (molekulare Sonden) für abstandsabhängige Messungen mittels Förster-Resonanz-Energietransfer (FRET) und zum anderen Sensorfluorophore, basierend auf einem DBD-Fluorophor und BAPTA, zur Messung der intrazellulären Calcium-Konzentration dargestellt. Für die Synthese von molekularen Sonden für abstandsabhängige Messungen wurden verschiedenste einfach- und doppelt-markierte OS(T)K-Stäbe entwickelt und spektroskopisch untersucht. Die OS(T)K-Stäbe, sogenannte molekulare Stäbe, dienten als starre Abstandshalter zwischen den Fluorophoren. Als Fluorophore wurden Derivate von 6,7-Dihydroxy-4-methylcoumarin (Donor) und Acyl-DBD (Akzeptor) verwendet, die zusammen ein FRET-Paar bilden. Die Fluorophore wurden so funktionalisiert, dass sie sowohl unbeweglich bzw. „starr“, als auch beweglich bzw. „flexibel“ an den OS(T)K-Stab gebunden werden konnten. Für die Synthese der OS(T)K-Stäbe wurden ebenfalls eine Reihe an unterschiedlich langen und kurzen Stabbausteinen synthetisiert. Auf diese Weise wurden eine Vielzahl an verschiedensten einfach- und doppelt-markierten OS(T)K-Stäben dargestellt, deren Fluorophore sowohl „starr“ als auch „flexibel“ gebunden sind. Die dargestellten Stäbe wurden in verschiedensten Lösungsmitteln spektroskopisch untersucht, um anschließend das Verhalten in Vesikel, die eine biomimetische Umgebung darstellen, zu beurteilen. Es wurde festgestellt, dass sich die Stäbe erfolgreich in die Vesikelmembran einlagerten und hohe FRET-Effizienzen aufweisen. Des Weiteren wurde ein FRET-Paar dargestellt, das sich durch 2-Photonenabsorpion im NIR-Bereich anregen lässt. Es wurde in den lebenden Zellen mittels Fluoreszenzlebenszeitmikroskopie (FLIM) untersucht. Zur Untersuchung von intrazellulärem Calcium wurden zwei verschiedene DBD-Fluorophore über einen kurzen Linker mit dem Calcium-Chelator BAPTA verknüpft. Die dargestellten Fluorophore wurden sowohl in vitro als auch in vivo auf ihre Calcium-Sensitivität überprüft. Mittels FLIM wurden in lebenden Zellen die Fluoreszenzlebenszeitverteilungen der Fluorophore nach Calcium-Konzentrationsänderungen detektiert. N2 - In this work, Oligospiro(thio)ketal (OS(T)K)-based model systems (molecular probes) for distance-dependent measurements by Förster resonance energy transfer (FRET) and sensor dyes, based on [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) dyes and BAPTA, for measuring the intracellular calcium concentration, were presented. For synthesis of molecular probes, for distance-dependent measurements, various single and double-labeled OS(T)K rods were developed and examined spectroscopically. The OS(T)K rods, called molecular rods, served as rigid spacers between the fluorophores. The FRET pairs consist of a Coumarin (Cou) dye as donor and a DBD dye as acceptor. Cou and DBD were functionalized in such a way that they could be connected both "rigid" as well as "flexible" to the OS(T)K rod. For synthesis of the OS(T)K rods, a number of different long and short rod units were synthesized. In this way, a variety of different single- and double-labeled OS(T)K rods were presented. The rods were spectroscopically analyzed in various solvents to subsequently evaluate the behavior in large unilamellar vesicles (LUVs) that represent a biomimetic system for cell membranes. It was found that the rods successfully incorporated in the vesicle membrane. Furthermore, a FRET pair was shown that can be excited by 2-photon absorption in the NIR region. It was examined in living cells by fluorescence lifetime microscopy (FLIM). To study intracellular calcium, two different DBD dyes were linked via a short linker to the calcium chelator BAPTA. The dyes were examined for their calcium sensitivity both in vitro and in vivo. Using FLIM, the fluorescence lifetime distributions of the dyes were detected in living cells after calcium concentration changes. KW - DBD KW - Coumarin KW - FRET KW - BAPTA KW - Calcium KW - 2P-FRET KW - OSK KW - OSTK KW - molekulare Stäbe KW - DBD KW - coumarin KW - FRET KW - BAPTA KW - calcium KW - 2P-FRET KW - OSK KW - OSTK KW - molecular rods Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-404213 ER -