Ganesh Babu Manoharan will defend his doctoral thesis titled "Combining chemical and genetic approaches for photoluminescence assays of protein kinases" on 29 March at 10:00 at UT Chemicum (Ravila Str. 14a, room 1021).
Supervisor: Asko Uri (PhD), TÜ Keemia Instituut
Opponent: Ruslan Dmitriev (PhD), University College Cork, Ireland
Summary: In this study, joint application of chemical and genetic approaches was used for construction of sensor systems for analysis of protein kinases.
Phosphorylation reaction is an important post-translational protein modification procedure in cells, which is carried out by protein kinases (PKs). This modification leads to increase in the diversity of the proteome that influences various aspects of normal and pathological physiology. Dysregulation of protein phosphorylation balances, caused by the aberrant activity of PKs is a cause or consequence of several complex diseases such as cancers, inflammatory disorders, cardio-vascular diseases and diabetes. Therefore PKs have become important drug targets in the 21st century. In recent 15 years, 30 small-molecule PK inhibitors have been approved for use in clinical practice.
In addition to being a potential drug targets, PKs also serve as biomarkers for cancers and other diseases, as altered expression level of various PKs is observed in a variety of malignancies. Thus there is high demand for analytical methods that enable determination of expression and activity levels of specific PKs in clinical samples, such as bodily fluids and cancerous tissues. Thus high throughput assays for screening PK inhibitors also form an important component of drug development pipeline.
During the last decade, it has been understood that merging of two disciplines, synthetic chemistry and protein engineering, is needed to construct molecules and their complexes with new functionalities that can create novel opportunities for biomedical research, drug development and disease diagnostics.
In this thesis combination of chemical and genetic approaches was used for the development of analytical tools for the characterization of PKs and PK inhibitors. PKs (PKAc, CK2α, and PIM kinases) were fused with fluorescent proteins (FPs). On the other hand, ARC-based small-molecule PK inhibitors were developed into protein binding-responsive ARC-Lum probes possessing unique photoluminescent properties. Joint application of PKs fused with fluorescent proteins and ARC-Lum probes enabled the construction of sensor systems that can be used for specific and sensitive determination of PKs in biological samples and as research tools for mapping and monitoring PK activity in living cells.