TY  - JOUR
A1  - Schwarze, Thomas
A1  - Mertens, Monique
A1  - Mueller, Peter
A1  - Riemer, Janine
A1  - Wessig, Pablo
A1  - Holdt, Hans-Jürgen
T1  - Highly K+-Selective Fluorescent Probes for Lifetime Sensing of K+ in Living Cells
JF  - Chemistry - a European journal
N2  - The new K+-selective fluorescent probes 1 and 2 were obtained by Cu-I-catalyzed 1,3-dipolar azide alkyne cycloaddition (CuAAC) reactions of an alkyne-substituted [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) ester fluorophore with azido-functionalized N-phenylaza-18-crown-6 ether and N-(o-isopropoxy) phenylaza-18-crown-6 ether, respectively. Probes 1 and 2 allow the detection of K+ in the presence of Na+ in water by fluorescence enhancement (2.2 for 1 at 2000mm K+ and 2.5 for 2 at 160mm K+). Fluorescence lifetime measurements in the absence and presence of K+ revealed bi-exponential decay kinetics with similar lifetimes, however with different proportions changing the averaged fluorescence decay times ((f(av))). For 1 a decrease of (f(av)) from 12.4 to 9.3ns and for 2 an increase from 17.8 to 21.8ns was observed. Variation of the substituent in ortho position of the aniline unit of the N-phenylaza-18-crown-6 host permits the modulation of the K-d value for a certain K+ concentration. For example, substitution of H in 1 by the isopropoxy group (2) decreased the K-d value from >300mm to 10mm. 2 was chosen for studying the efflux of K+ from human red blood cells (RBC). Upon addition of the Ca2+ ionophor ionomycin to a RBC suspension in a buffer containing Ca2+, the fluorescence of 2 slightly rose within 10min, however, after 120min a significant increase was observed.
KW  - electron transfer
KW  - fluorescence lifetime
KW  - fluorescent probes
KW  - living cells
KW  - potassium
Y1  - 2017
U6  - https://doi.org/10.1002/chem.201704368
SN  - 0947-6539
SN  - 1521-3765
VL  - 23
SP  - 17186
EP  - 17190
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - Merkel, Roswitha
A1  - Mueller, Peter
T1  - Articulated rods - a novel class of molecular rods based on oligospiroketals (OSK)
JF  - Beilstein journal of organic chemistry
N2  - We developed a new type of molecular rods consisting of two (or more) rigid units linked by a flexible joint. Consequently we called these constructs articulated rods (ARs). The syntheses of ARs were carried out by a flexible and modular approach providing access to a number of compounds with various functionalizations in terminal positions. First applications were presented with pyrene, cinnamoyl and anthracenyl labelled ARs.
KW  - articulated rods
KW  - click chemistry
KW  - molecular rods
KW  - oligospiroketals
KW  - pyrene excimer
Y1  - 2015
U6  - https://doi.org/10.3762/bjoc.11.11
SN  - 1860-5397
VL  - 11
SP  - 74
EP  - 84
PB  - Beilstein-Institut zur Förderung der Chemischen Wissenschaften
CY  - Frankfurt, Main
ER  - 
TY  - JOUR
A1  - Haralampiev, Ivan
A1  - Mertens, Monique
A1  - Schwarzer, Roland
A1  - Herrmann, Andreas
A1  - Volkmer, Rudolf
A1  - Wessig, Pablo
A1  - Mueller, Peter
T1  - Recruitment of SH-Containing peptides to lipid and biological membranes through the use of a palmitic acid functionalized with a Maleimide Group
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - This study presents a novel and easily applicable approach to recruit sulfhydryl-containing biomolecules to membranes by using a palmitic acid which is functionalized with a maleimide group. Notably, this strategy can also be employed with preformed (biological) membranes. The applicability of the assay is demonstrated by characterizing the binding of a Rhodamine-labeled peptide to lipid and cellular membranes using methods of fluorescence spectroscopy, lifetime measurement, and microscopy. Our approach offers new possibilities for preparing biologically active liposomes and manipulating living cells.
KW  - liposomes
KW  - maleimide
KW  - membranes
KW  - palmitic acid
KW  - palmitoylation
KW  - peptides
Y1  - 2015
U6  - https://doi.org/10.1002/anie.201408089
SN  - 1433-7851
SN  - 1521-3773
VL  - 54
IS  - 1
SP  - 323
EP  - 326
PB  - Wiley-VCH
CY  - Weinheim
ER  -