TY - JOUR A1 - Sloniec, Jagoda A1 - Schnurr, M. A1 - Witte, C. A1 - Resch-Genger, Ute A1 - Schröder, L. A1 - Hennig, Andreas T1 - Biomembrane interactions of functionalized cryptophane-A: combined fluorescence and 129Xe NMR studies of a bimodal contrast agent N2 - Fluorescent derivatives of the 129Xe NMR contrast agent cryptophane-A were obtained by functionalization with near infrared fluorescent dyes DY680 and DY682. The resulting conjugates were spectrally characterized, and their interaction with giant and large unilamellar vesicles of varying phospholipid composition was analyzed by fluorescence and NMR spectroscopy. In the latter, a chemical exchange saturation transfer with hyperpolarized 129Xe (Hyper-CEST) was used to obtain sufficient sensitivity. To determine the partitioning coefficients, we developed a method based on fluorescence resonance energy transfer from Nile Red to the membrane-bound conjugates. This indicated that not only the hydrophobicity of the conjugates, but also the phospholipid composition, largely determines the membrane incorporation. Thereby, partitioning into the liquid-crystalline phase of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine was most efficient. Fluorescence depth quenching and flip-flop assays suggest a perpendicular orientation of the conjugates to the membrane surface with negligible transversal diffusion, and that the fluorescent dyes reside in the interfacial area. The results serve as a basis to differentiate biomembranes by analyzing the Hyper-CEST signatures that are related to membrane fluidity, and pave the way for dissecting different contributions to the Hyper-CEST signal. KW - Biosensors KW - Fluorescence KW - FRET KW - Hyperpolarization KW - Lipids KW - Xenon PY - 2013 DO - https://doi.org/10.1002/chem.201203773 SN - 0947-6539 SN - 1521-3765 VL - 19 IS - 9 SP - 3110 EP - 3118 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-28980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sloniec, Jagoda A1 - Resch-Genger, Ute A1 - Hennig, Andreas T1 - Enzyme- Activatable NIR Fluorescent Probes Quenched by Intramolecular H-Aggregate Formation T2 - International Photochemistry Conference ICP2013 CY - Leuven, Belgium DA - 2013-06-21 PY - 2013 AN - OPUS4-28957 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sloniec, Jagoda A1 - Resch-Genger, Ute A1 - Hennig, Andreas T1 - Efficiently Quenched Fluorescent NIR Probe for Detection of Enzyme Activity T2 - 23rd Lecture Conference on Photochemistry CY - Potsdam, Germany DA - 2012-10-08 PY - 2012 AN - OPUS4-26670 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sloniec, Jagoda A1 - Resch-Genger, Ute A1 - Hennig, Andreas T1 - Photophysics and release kinetics of enzyme-activatable optical probes based on H-dimerized fluorophores on self-immolative linkers N2 - A series of activatable optical probes for the model enzyme penicillin G amidase based on intramolecular formation of non-fluorescent H-dimer between two identical dyes were synthesized. The probes are based on a self-immolative linker, which allows positioning both dyes in close spatial proximity to ensure efficient quenching of probes with absorption and fluorescence emission in the near-infrared (NIR) range. A detailed photophysical investigation of the novel optical probes led to a revision of a previously anticipated quenching mechanism and revealed their potential for optimizing the performance of activatable probes based on H-dimer formation. A kinetic analysis indicated that the fluorescence progress curves can be used to qualitatively extract enzyme kinetic parameters. PY - 2013 DO - https://doi.org/10.1021/jp409388b SN - 1520-6106 SN - 1520-5207 SN - 1089-5647 VL - 117 IS - 46 SP - 14336 EP - 14344 PB - Soc. CY - Washington, DC AN - OPUS4-30053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Sloniec-Myszk, Jagoda ED - Hennig, Andreas T1 - Chiral, J-aggregate-forming dyes for alternative signal modulation mechanisms in self-immolative enzyme-activatable optical probes N2 - Enzyme-activatable optical probes are important for future advances in cancer imaging, but may easily suffer from low signal-to-background ratios unless not optimized. To address this shortcoming, numerous mechanisms to modulate the fluorescence signal have been explored. We report herein newly synthesized probes based on selfimmolative linkers containing chiral J-aggregate-forming dyes. Signal modulation by formation of chiral J-aggregates is yet unexplored in optical enzyme probe design. The comprehensive characterization of the probes by absorption, CD, fluorescence, and time-resolved fluorescence spectroscopy revealed dye−dye interactions not observed for the free dyes in solution as well as dye−protein interactions with the enzyme. This suggested that J-aggregate formation is challenging to achieve with current probe design and that interactions of the dyes with the Enzyme may interfere with achieving high signal-to-background ratios. The detailed understanding of the interactions provided herein provides valuable guidelines for the future design of similar probes. KW - Signal amplification KW - Fluorescence KW - Quantum yield KW - Optical spectroscopy KW - Dye KW - Cyanine KW - Characterization KW - Assay KW - Chiral KW - Aggregation KW - Activatable probe PY - 2016 DO - https://doi.org/10.1021/acs.jpcb.5b10526 SN - 1520-5207 SN - 1520-6106 VL - 120 IS - 5 SP - 877 EP - 885 PB - ACS Publications AN - OPUS4-35949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -