X-ray structures and feasibility assessment of CLK2 inhibitors for Phelan McDermid syndrome.
ChemMedChem. 2018 Jul 09;:
Authors: Lerchner AM, Kallen J, Bergsdorf C, Arnaud B, Bernhard M, Brichet M, Cobos-Correa A, Elhajouji A, Freuler F, Galimberti I, Guibourdenche C, Haenni S, Holzinger S, Hunziker J, Izaac A, Kaufmann M, Leder L, Martus HJ, von Matt P, Polyakov V, Roethlisberger P, Roma G, Stiefl N, Uteng M
CLK2 inhibition has been proposed as a potential mechanism to improve autism and neuronal functions in Phelan-McDermid syndrome (PMDS). Herein, we report the discovery of a very potent indazole CLK inhibitor series, and the CLK2 X-ray structure of its most potent analog. This new indazole series was identified via a biochemical CLK2 Caliper assay screen with 30k compounds that were selected by an in silico approach. Novel high resolution X-ray structures of all CLKs, including the first CLK4 X-ray structure, bound to known CLK2 inhibitor tool compounds (e.g. TG003, CX-4945), are also shown and yield insights into inhibitor selectivity in the CLK family. Efficacy of our new CLK2 inhibitors from the indazole series was demonstrated in the mouse brain slice assay, and potential safety concerns were investigated. We show genotoxicity findings in the human lymphocyte MNT assay using two structurally different CLK inhibitors, which reveals a major concern for pan-CLK inhibition in PMDS.
PMID: 29985556 [PubMed – as supplied by publisher]