Benzobisthiazoles Represent a Novel Scaffold for Kinase Inhibitors of CLK Family Members.

Krisna Prak,Christin Luft,Joana R Costa,Robin Ketteler,Janos Kriston-Vizi,A W Edith Chan,Niccolo Pengo

doi:10.1021/acs.biochem.5b01128

Krisna Prak, Christin Luft + Show 5 more

Open Access

https://doi.org/10.1021/acs.biochem.5b01128

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Abstract

Protein kinases are essential regulators of most cellular processes and are involved in the etiology and progression of multiple diseases. The cdc2-like kinases (CLKs) have been linked to various neurodegenerative disorders, metabolic regulation, and virus infection, and the kinases have been recognized as potential drug targets. Here, we have developed a screening workflow for the identification of potent CLK2 inhibitors and identified compounds with a novel chemical scaffold structure, the benzobisthiazoles, that has not been previously reported for kinase inhibitors. We propose models for binding of these compounds to CLK family proteins and key residues in CLK2 that are important for the compound interactions and the kinase activity. We identified structural elements within the benzobisthiazole that determine CLK2 and CLK3 inhibition, thus providing a rationale for selectivity assays. In summary, our results will inform structure-based design of CLK family inhibitors based on the novel benzobisthiazole scaffold.

Highlights

Protein kinases control and modulate a wide variety of biological processes through their catalytic activity,[1,2] including signal transduction and gene splicing
To identify small molecule inhibitors of the cdc2-like kinases (CLKs) family of proteins, we developed an in vitro kinase assay for CLK2 that is amenable to high-throughput drug screening
We calculated the catalytic rates of the enzyme and the mutants (Figure 1D) and found that the Kcat/Km values of GST-CLK2cdK193A/D290A, GST-CLK2cdK193A, and GSTCLK2cd were 2.6 × 10−4, 27.8 × 10−4, and 143.2 × 10−4 M−1 s−1, respectively, which indicated that the K193A mutation or K193A/D290A double mutation leads to the catalytic activity of CLK2 being decreased >5- or >54-fold, respectively

Summary

Introduction

Protein kinases control and modulate a wide variety of biological processes through their catalytic activity,[1,2] including signal transduction and gene splicing. We studied structural determinants in CLK2 that contribute to ATP binding and catalytic activity to rationalize compound binding. We conducted small molecule screening for the identification of novel CLK2 inhibitors and investigated the selectivity of the compounds on the basis of the kinase crystal structures, the molecular docking, and kinase inhibition assays.

Results

Conclusion