Ligand identification

Interaction of small molecule ligands with therapeutically relevant proteins

In times of frequent resistance to known drugs, finding new substances that attack target structures more potently and selectively is becoming increasingly important. Therefore, one research focus of the Center for Pharmacology is the investigation of molecular interactions of small molecule, drug-like compounds (ligands) with medically or therapeutically relevant target structures, such as enzymes and protein-protein interactions. This is done in close collaboration with research groups from Medical and Mathematical-Scientific Faculties of various universities and with external research institutions.

A variety of working techniques are used, such as cell and bacterial culture, expression of recombinant proteins, analysis and quantification of the interaction of ligands with their target structures - primarily by spectrophotometric and fluorometric methods - as well as the evaluation of these interactions with the aid of various mathematical models.

For further information, please get in touch with Dr. Markus Pietsch.

Development of novel inhibitors of the tumor-relevant protein kinase CK2

In this project, the interaction of the subunits of protein kinase CK2 (CK2α or CK2α' and CK2β) and the impact of inhibitors on it is investigated. Protein kinase CK2 is overexpressed in various tumors and promotes tumor cell survival through its anti-apoptotic effect. An alternative approach is being pursued for the development of inhibitors of the enzyme. The pharmacological target is not the active site of the kinase but the binding site of the CK2 subunits. This should lead to inhibitors that are, on the one hand, more selective in their biological effect and, on the other hand, can be used as tools to study the cellular effects of a disturbed quaternary structure of CK2. For the initial identification and analysis of such inhibitors, several newly developed binding assays using the human CK2 subunits (recombinantly expressed in E. coli) and a CK2β-derived peptide are employed. Furthermore, the inhibitory effect on the kinase activity of CK2 and the cytotoxic effect of the compounds on tumor and non-tumor cells are investigated.

Selected Publications:
Kröger, L.; Daniliuc, C. G.; Ensan, D.; Borgert, S.; Nienberg, C.; Lauwers, M.; Steinkrüger, M.; Jose, J.; Pietsch, M.; Wünsch, B. Synthesis and SAR of tetracyclic inhibitors of protein kinase CK2 derived from furocarbazole W16. ChemMedChem 2020, 15, 871-881.[Pubmed]
 
Pietsch, M.; Viht, K.; Schnitzler, A.; Ekambaram, R.; Steinkrüger, M.; Enkvist, E.; Nienberg, C.; Nickelsen, A.; Lauwers, M.; Jose, J.; Uri, A.; Niefind, K. Unexpected CK2β-antagonistic functionality of bisubstrate inhibitors targeting protein kinase CK2. Bioorg. Chem. 2020, 96:103608.[Pubmed]
 
Lindenblatt, D.; Horn, M.; Götz, C.; Niefind, K.; Neundorf, I.; Pietsch, M. Design of CK2β-mimicking peptides as tools to study the CK2α/CK2β interaction in cancer cells. ChemMedChem 2019, 14, 833-841.[Pubmed
 
Hochscherf, J.; Lindenblatt, D.; Steinkrüger, M.; Yoo, E.; Ulucan, Ö.; Herzig, S.; Issinger, O.-G.; Helms, V.; Götz, C.; Neundorf, I.; Niefind, K.; Pietsch, M. Development of a HTS-compatible assay to identify inhibitors of the CK2a/CK2ß interaction. Anal. Biochem. 2015, 468, 4-14.[Pubmed]

Development of inhibitors of the tumor-relevant transglutaminase 2

The project aims to develop new inhibitors of the enzyme transglutaminase 2 (TGase 2). The expression of TGase 2 is upregulated in various tumor types and correlates with their chemo- and radioresistance as well as their invasive potential. In this project, small molecules are synthesized and kinetically characterized with regard to their inhibitory properties towards TGase 2 and other transglutaminases. Fluorescence- and fluorescence anisotropy-based assays necessary to determine the hydrolase and transamidase activities of TGase 2, respectively, have already been developed, and novel inhibitors have been kinetically characterized on recombinant human TGase 2 as well as on TGase 2 from guinea pig liver. Ongoing studies address the optimization of already identified active site inhibitors and the development of novel, allosterically acting inhibitors, including assay methods to quantify their inhibitory potential. The obtained information will then be used to design radiolabeled probes for diagnosing or treating various tumor diseases.

Selected Publications:
Hauser, S.; Sommerfeld, P.; Wodtke, J.; Hauser, C.; Schlitterlau, P.; Pietzsch, J.; Löser, R.; Pietsch, M.; Wodtke, R. Application of a fluorescence anisotropy-based assay to quantify transglutaminase 2 activity in cell lysates. Int. J. Mol. Sci. 2022, 23:4475.[Pubmed]
 
Wodtke, R.: Wodtke, J.; Hauser, S.; Laube, M.; Bauer, D.; Rothe, R.; Neuber, C.; Pietsch, M.; Kopka, K.; Pietzsch, J. Löser, R. Development of an 18F-labeled irreversible inhibitor of transglutaminase 2 as radiometric tool for quantitative expression profiling in cells and tissues. J. Med. Chem. 2021, 64, 3462-3478.[Pubmed]
 
Wodtke, R.; Hauser, C.; Ruiz-Gómez, G.; Jäckel, E.; Bauer, D.; Lohse, M.; Wong, A.; Pufe, J.; Ludwig, F.-A.; Fischer, S.; Hauser, S.; Greif, D.; Pisabarro, M. T.; Pietzsch, J.; Pietsch, M.; Löser, R. Nԑ-Acryloyllysine piperazides as irreversible inhibitors of transglutaminase 2: Synthesis, struc-ture-activity relationships, and pharmacokinetic profiling. J. Med. Chem. 2018, 61, 4528-4560.[Pubmed]
 
Hauser, C.;* Wodtke, R.;* Löser, R.;# Pietsch, M.# A fluorescence anisotropy-based assay for determining the activity of tissue transglutaminase. Amino Acids 2017, 49, 567-583.[Pubmed
*, # C. Hauser und R. Wodtke sowie R. Löser und M. Pietsch haben jeweils zu gleichen Teilen zur Publikation beigetragen.
 
Wodtke, R.; Schramm, G.; Pietzsch, J.; Pietsch, M.; Löser, R. Synthesis and kinetic characterisation of water-soluble fluorogenic acyl donors for transglutaminase 2. ChemBioChem 2016, 17, 1263-1281. Corrigendum: ChemBioChem 2016, 17, 1674.[Pubmed][Corrigendum]

Development of inhibitors of the serine hydrolases cholesterol esterase, monoacylglycerol lipase, and fatty acid amide hydrolase as anti-inflammatory substances

Bile salt-dependent cholesterol esterase (CEase) is involved in inflammatory processes, such as atherosclerosis and rheumatoid arthritis, and is, therefore, a target for inhibitor development. To determine the CEase activity, a new fluorimetric assay was developed and evaluated on human, mouse (both recombinantly expressed in HEK-293 EBNA cells), and bovine pancreatic enzymes using inhibitors known from the literature. To assess the selectivity of identified CEase inhibitors, the recombinantly generated human serine hydrolases monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH), which cleave similar substrates to CEase and are themselves targets in various diseases/pathological processes, including cancer, pain, inflammation as well as cardiovascular disease, are also investigated. Spectrophotometric or fluorimetric activity assays to characterize inhibitors have also been established for these two enzymes. Preliminary studies on the three enzymes show that ω-phthalimidoalkyl aryl ureas act as potent inhibitors of murine and human CEase and exhibit significantly lower inhibitory activity towards MAGL and FAAH. In contrast, the structurally related ω-quinazolinonylalkyl aryl ureas act primarily as reversible inhibitors of MAGL.

For further information, please get in touch with Dr. Markus Pietsch.

Selected Publications:
Dato, F. M.; Neudörfl, J. M.; Gütschow, M.; Goldfuss, B.; Pietsch, M. ω-Quinazolinonylalkyl aryl ureas as reversible inhibitors of monoacylglycerol lipase. Bioorg. Chem. 2020, 94:103352.[Pubmed]
 
Dato, F. M.; Sheikh, M.; Uhl, R. Z.; Schüller, A. W.; Steinkrüger, M.; Koch, P.; Neudörfl, J.-M.; Gütschow, M.; Goldfuß, B.; Pietsch, M. ω-Phthalimidoalkyl aryl ureas as potent and selective inhibitors of cholesterol esterase. ChemMedChem 2018, 13, 1833-1847.[Pubmed
 
Dato, F. M.; Maaßen, A.; Goldfuß, B.; Pietsch, M. Characterization of fatty acid amide hydrolase activity by a fluorescence-based assay. Anal. Biochem. 2018, 546, 50-57.[Pubmed]