TY  - JOUR
A1  - Schulte, Clemens
A1  - Soldà, Alice
A1  - Spänig, Sebastian
A1  - Adams, Nathan
A1  - Bekić, Ivana
A1  - Streicher, Werner
A1  - Heider, Dominik
A1  - Strasser, Ralf
A1  - Maric, Hans Michael
T1  - Multivalent binding kinetics resolved by fluorescence proximity sensing
JF  - Communications Biology
N2  - Multivalent protein interactors are an attractive modality for probing protein function and exploring novel pharmaceutical strategies. The throughput and precision of state-of-the-art methodologies and workflows for the effective development of multivalent binders is currently limited by surface immobilization, fluorescent labelling and sample consumption. Using the gephyrin protein, the master regulator of the inhibitory synapse, as benchmark, we exemplify the application of Fluorescence proximity sensing (FPS) for the systematic kinetic and thermodynamic optimization of multivalent peptide architectures. High throughput synthesis of +100 peptides with varying combinatorial dimeric, tetrameric, and octameric architectures combined with direct FPS measurements resolved on-rates, off-rates, and dissociation constants with high accuracy and low sample consumption compared to three complementary technologies. The dataset and its machine learning-based analysis deciphered the relationship of specific architectural features and binding kinetics and thereby identified binders with unprecedented protein inhibition capacity; thus, highlighting the value of FPS for the rational engineering of multivalent inhibitors.
KW  - combinatorial libraries
KW  - kinetics
KW  - peptides
KW  - screening
KW  - thermodynamics
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-301157
VL  - 5
ER  - 
TY  - JOUR
A1  - Hoyer, Jan
A1  - Schatzschneider, Ulrich
A1  - Schulz-Siegmund, Michaela
A1  - Neundorf, Ines
T1  - Dimerization of a cell-penetrating peptide leads to enhanced cellular uptake and drug delivery
JF  - Beilstein Journal of Organic Chemistry
N2  - Over the past 20 years, cell-penetrating peptides (CPPs) have gained tremendous interest due to their ability to deliver a variety of therapeutically active molecules that would otherwise be unable to cross the cellular membrane due to their size or hydrophilicity. Recently, we reported on the identification of a novel CPP, sC18, which is derived from the C-terminus of the 18 kDa cationic antimicrobial protein. Furthermore, we demonstrated successful application of sC18 for the delivery of functionalized cyclopentadienyl manganese tricarbonyl (cymantrene) complexes to tumor cell lines, inducing high cellular toxicity. In order to increase the potential of the organometallic complexes to kill tumor cells, we were looking for a way to enhance cellular uptake. Therefore, we designed a branched dimeric variant of sC18, (sC18)\(_2\), which was shown to have a dramatically improved capacity to internalize into various cell lines, even primary cells, using flow cytometry and fluorescence microscopy. Cell viability assays indicated increased cytotoxicity of the dimer presumably caused by membrane leakage; however, this effect turned out to be dependent on the specific cell type. Finally, we could show that conjugation of a functionalized cymantrene with (sC18)\(_2\) leads to significant reduction of its IC\(_{50}\) value in tumor cells compared to the respective sC18 conjugate, proving that dimerization is a useful method to increase the drug-delivery potential of a cell-penetrating peptide.
KW  - peptides
KW  - internalization studies
KW  - drug delivery
KW  - cell-penetrating peptides
KW  - anti-tumor agents
KW  - organometallic complexes
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133933
VL  - 8
ER  -