The goal of this project is to identify the molecular targets of antiinfectives with potent activity in phenotypic biological assays. Because many of antibacterial and antiviral compounds have been discovered in phenotypic assays, methods to identify their mode of action are of high concrete as well as general strategic importance. The most general method to discover molecular binding partners of small molecules is a target fishing workflow. A chemoproteomic approach, which utilize chemical probes to identify target proteins. In this thesis the Affinity Based (AfPP) as well as the Activity Based Protein Profiling (ABPP) is applied in two different projects.
For the first project, different photoprobes are synthesized based on recently discovered lead compounds against alpha hemolysin, a virulence factor of Staphylococcus aureus. Highly potent photoprobes are then used in photoaffinity labeling experiments. A subsequent sample preparation including protein digestion deliver peptides, which are analyzed by tandem mass spectrometry. Peptides, which are modified by the photoprobe, will offer valuable clues to the mode of action of the lead compounds.
In the second project, an activity based probe which relies on a natural product discovered lately at the TU Braunschweig is employed. The strong binding of biotin to streptavidin is exploited in pull down assays to enrich a potential target protein. First successful protein enrichment could be already carried out and is now followed by functional assays to prove an inhibiting effect.
Name of Doctoral Researcher
Karoline Jerye
Name of Supervisor
Mark Brönstrup
Institute / Department
Chemical Biology, HZI
Contact details
karoline.jerye@helmholtz-hzi.de