TY  - JOUR
A1  - Techen, Anne
A1  - Czapla, Sylvia
A1  - Möllnitz, Kristian
A1  - Budach, Dennis B.
A1  - Wessig, Pablo
A1  - Kumke, Michael Uwe
T1  - Synthesis and spectroscopic characterization of fluorophore-labeled oligospiroketal rods
JF  - Helvetica chimica acta
N2  - Fluorescence probes consisting of well-established fluorophores in combination with rigid molecular rods based on spirane-type structures were investigated with respect to their fluorescence properties under different solvent conditions. The attachment of the dyes was accomplished by 1,3-dipolar cycloaddition between alkynes and azides (click' reaction) and is a prime example for a novel class of sensor constructs. Especially, the attachment of two (different) fluorophores on opposite sides of the molecular rods paves the way to new sensor systems with less bulky (compared to the conventional DNA- or protein-based concepts), nevertheless rigid spacer constructs, e.g., for FRET-based sensing applications. A detailed photophysical characterization was performed in MeOH (and in basic H2O/MeOH mixtures) for i) rod constructs containing carboxyfluorescein, ii) rod constructs containing carboxyrhodamine, iii) rod constructs containing both carboxyfluorescein and carboxyrhodamine, and iv) rod constructs containing both pyrene and perylene parts. For each dye (pair), two rod lengths with different numbers of spirane units were synthesized and investigated. The rod constructs were characterized in ensemble as well as single-molecule fluorescence experiments with respect to i) specific roddye and ii) dyedye interactions. In addition to MeOH and MeOH/NaOH, the rod constructs were also investigated in micellar systems, which were chosen as a simplified model for membranes.
KW  - Molecular rods
KW  - Forster resonance energy transfer (FRET)
KW  - Carboxyfluorescein
KW  - Carboxyrhodamine
KW  - Pyrene
KW  - Perylene
KW  - Fluorescence
Y1  - 2013
U6  - https://doi.org/10.1002/hlca.201200616
SN  - 0018-019X
SN  - 1522-2675
VL  - 96
IS  - 11
SP  - 2046
EP  - 2067
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Samaha, Doaa
A1  - Hamdo, Housam H.
A1  - Cong, Xiaojing
A1  - Schumacher, Fabian
A1  - Banhart, Sebastian
A1  - Aglar, Öznur
A1  - Möller, Heiko Michael
A1  - Heuer, Dagmar
A1  - Kleuser, Burkhard
A1  - Saied, Essa M.
A1  - Arenz, Christoph
T1  - Liposomal FRET assay identifies potent drug-like inhibitors of the Ceramide Transport Protein (CERT)
JF  - Chemistry - a European journal
N2  - Ceramide transfer protein (CERT) mediates non-vesicular transfer of ceramide from endoplasmic reticulum to Golgi apparatus and thus catalyzes the rate-limiting step of sphingomyelin biosynthesis. Usually, CERT ligands are evaluated in tedious binding assays or non-homogenous transfer assays using radiolabeled ceramides. Herein, a facile and sensitive assay for CERT, based on Forster resonance energy transfer (FRET), is presented. To this end, we mixed donor and acceptor vesicles, each containing a different fluorescent ceramide species. By CERT-mediated transfer of fluorescent ceramide, a FRET system was established, which allows readout in 96-well plate format, despite the high hydrophobicity of the components. Screening of a 2 000 compound library resulted in two new potent CERT inhibitors. One is approved for use in humans and one is approved for use in animals. Evaluation of cellular activity by quantitative mass spectrometry and confocal microscopy showed inhibition of ceramide trafficking and sphingomyelin biosynthesis.
KW  - enzyme assays
KW  - Forster resonance energy transfer (FRET)
KW  - liposomes
KW  - sphingolipids
KW  - transport proteins
Y1  - 2020
U6  - https://doi.org/10.1002/chem.202003283
SN  - 0947-6539
SN  - 1521-3765
VL  - 26
IS  - 70
SP  - 16616
EP  - 16621
PB  - Wiley-VCH
CY  - Weinheim
ER  -