Chemokine receptor CXCR3: Allosteric binding site mapping by photoaffinity labeling and site-directed mutagenesis
Final Report Abstract
The grant deals with a very attractive pharmacological target, for which the receptor-ligand interactions responsible for the high affinity and noncompetitive (allosteric) antagonism are not yet satisfactorily structurally and functionally characterized. Within the research funded we combined de novo synthesis with homology modelling and docking, site-directed mutagenesis and detailed pharmacological characterisation. With the aid of novel ligands, which were synthesized in my research group, the validation of obtained homology model and identified binding pocket was performed. From this series we have identified the first functionally selective and probe-dependent negative allosteric modulators of CXCR3, i.e. ligands that can selectively direct intracellular signalling conducted by the receptor to one of two possible pathways. Also, we developed the probes for photoaffinity labelling and developed a protocol for recombinant expression of CXCR3. Unfortunately, the preparation of probes for the microscale thermophoresis experiments proved more difficult than anticipated. Overall, the information gathered within this project provides a powerful platform for further development and rational design of strongly biased allosteric modulators of CXCR3 and is supported by ground-breaking publications.
Publications
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Synthesis and application of the first radioligand targeting the allosteric binding pocket of chemokine receptor CXCR3. ChemMedChem, 2012, 7(8):1481-1489
Bernat, V., Heinrich, M., Baumeister, P., Buschauer, A., Tschammer, N.
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Allosteric modulation of GPCRs: Chemokines and their receptors. In: Topics in Medicinal Chemistry, Springer Verlag, 2014
Tschammer, N., Kenakin, T., Christopoulos, A.
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Boronic acids as probes for investigation of allosteric regulation of the chemokine receptor CXCR3. ACS Chem. Biol., 2014, 9(11): 2664-2677
Bernat, V., Brox, R. Haimanot Admas, T., Tschammer, N.
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Identifying modulators of CXC receptors 3 and 4 with tailored selectivity using multi-target docking. ACS Chem. Biol., 2015, 10 (3): 715–724
Schmidt, D., Bernat, V., Brox, R., Tschammer, N., Kolb, P.
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Ligand biased and probe-dependent modulation of the chemokine receptor CXCR3 signaling by negative allosteric modulators. ChemMedChem. 2015, 10(3): 566-574
Bernat, V., Brox, R. Heinrich, M.R., Auberson, Y.P., Tschammer, N.
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(2016): Allosteric Modulators of the Class A G Protein Coupled Receptors. In: Advances in experimental medicine and biology 917, S. 185–207
Tschammer, N.
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Development of photoactivatable allosteric modulators for the chemokine receptor CXCR3. ChemMedChem. 2016, 11 (6): 575-584
Haimanot Admas, T., Bernat V., Heinrich, M.R., Tschammer, N.
