Evaluating the therapeutic viability of bacterially expressed human TLK1B-kinase domain for cancer drug design

The role of protein kinases is vital in diverse cellular functions. The alterations in the expression patterns of protein kinases often implicate human cancer initiation and progression. Human Tousled-like kinases (TLKs) are evolutionary kinases found in the cell signalling pathway and are involved in DNA repair, replication and chromosomal integrity. The direct association of TLKs to cancer; amplification of both TLK1/1B and TLK2 has made them viable molecular targets for anticancer therapy. Several reports demonstrate numerous functions of TLKs in development of disease via different interacting partners. However, a detailed understanding of its substrates and regulation has yet remained elusive. In this report, through preliminary biophysical and biochemical characterization, we investigate and determine the usability of the recombinant Human Tousled-like Kinase 1B-Kinase Domain (hTLK1B-KD) purified from Escherichia coli for structural and functional studies. By illustrating hTLK1B-KD as an example, our attempts to generate a stable, homogenously dephosphorylated, and catalytically active hTLK1B-KD in high yields is utilizing a bacteriophage ? protein phosphatase (LPP) coexpression system represents a fundamental step towards the structure-based design of TLK-specific inhibitors.