A Chemical Genetic Approach for Covalent Inhibition of Analogue-Sensitive Aurora Kinase

The perturbation of protein kinases with small organic molecules is a powerful approach to dissect kinase function in complex biological systems. Covalent kinase inhibitors that target thiols in the ATP binding pocket of the kinase domain proved to be ideal reagents for the investigation of highly dynamic cellular processes. However, due to the covalent inhibitors' possible off-target reactivities, it is required that the overall shape of the inhibitor as well as the intrinsic reactivity of the electrophile are precisely tuned to favor the reaction with only the desired cysteine. Here we report on the design and biological characterization of covalent anilinoquinazolines as potent inhibitors of genetically engineered Aurora kinase in fission yeast

The hit compounds were analyzed by Cytoscape and Chemmine for physicochemical parameters.

<p>Filtering compounds based Lipinski rule of five druglikeness (A) Molwt cutoff, (B) alogP (C) Hydrogen bond donors and (D) Hydrogen bond acceptors.</p

Complete analysis of data from screening for antitubercular activity and physico chemical properties of the hit compounds.

<p>Rifampicin and Isoniazid were taken as controls. MIC values for controls against <i>M</i>. <i>smegmatis</i> are Rif-2.43±0.02μM and Inh-11.03±0.05 μM and <i>H37Rv</i> are Rif-0.08±0.01μM and Inh-0.22±0.3 μM.</p

To improve the predictions of druglikeness other filters have been added to the analysis.

<p>The list of identified hit compounds have been filtered based on Veber Rules (A) PSA and (B) Number of rotatable Bonds.</p

Work flow.

<p>Small molecule library screening for anti mycobacterial potential, physicochemical properties following medicinal chemistry principles and cytotoxicity identified potential hit scaffolds.</p

Primary screening results.

<p>Using a z-score cutoff of 1.5, 150 compounds were identified actives against mycobacteria. The distribution of the z-score for the primary screen is shown here.</p

Cytotoxic evaluation of the hit compounds.

<p>Doxorubicin was taken as control. TI stands for therapeutic index calculated by IC₅₀/GI₅₀ value against <i>H37Rv</i>.</p

Clustering of actives identified in primary screening.

<p>All hit compounds identified were chemical clustered using pubchem finger prints. (A) The major cluster with five compounds maximum to minor cluster with three compounds and (B) doubles tons are shown here.</p