Analyzing Distinct Binding Modes of Diaminotriazole-Based Spastin Inhibitors Through Biochemical Resistance
44 Pages Posted: 16 Apr 2019 Sneak Peek Status: Review CompleteMore...
Drug-like inhibitors are often designed by mimicking cofactor or substrate interactions with enzymes. However, as active sites are comprised of conserved residues, it is difficult to identify the critical interactions needed to design selective inhibitors. We are developing an approach, named RADD (Resistance Analysis During Design), which involves engineering point mutations in the target to generate active alleles and testing compounds against them. Mutations that alter compound potency identify residues that make key interactions with the inhibitor and predict target-binding poses. Here, we apply this approach to analyze how diaminotriazole-based inhibitors bind spastin, a microtubule-severing AAA (ATPases associated with diverse activities) protein. The distinct binding poses predicted for two similar inhibitors were confirmed by a series of x-ray structures of inhibitor-spastin complexes. Importantly, our approach not only unravels how selective inhibition of the target can be achieved but also identifies resistance-conferring mutations at the early stages of the design process.
Keywords: chemical inhibitor, resistance, drug design, AAA protein, spastin, mutagenesis, x-ray crystallography
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