Novel Small Molecules Targeting the Intrinsically Disordered Structural Ensemble of α-Synuclein Protect Against Diverse α-Synuclein Mediated Dysfunctions

Abstract

The over-expression and aggregation of α-synuclein (αSyn) are linked to the onset and pathology of Parkinson's disease. Native monomeric αSyn exists in an intrinsically disordered ensemble of interconverting conformations, which has made its therapeutic targeting by small molecules highly challenging. Nonetheless, here we successfully target the monomeric structural ensemble of αSyn and thereby identify novel drug-like small molecules that impact multiple pathogenic processes. Using a surface plasmon resonance high-throughput screen, in which monomeric αSyn is incubated with microchips arrayed with tethered compounds, we identified novel αSyn interacting drug-like compounds. Because these small molecules could impact a variety of αSyn forms present in the ensemble, we tested representative hits for impact on multiple αSyn malfunctions in vitro and in cells including aggregation and perturbation of vesicular dynamics. We thereby identified a compound that inhibits αSyn misfolding and is neuroprotective, multiple compounds that restore phagocytosis impaired by αSyn overexpression, and a compound blocking cellular transmission of αSyn. Our studies demonstrate that drug-like small molecules that interact with native αSyn can impact a variety of its pathological processes. Thus, targeting the intrinsically disordered ensemble of αSyn offers a unique approach to the development of small molecule research tools and therapeutics for Parkinson's disease. 157 83.27 84 21 137 80.87 79

Chemical tools for study and modulation of biomolecular phase transitions

“…IDPs are therefore oen avoided in high-throughput screens for small-molecule effectors due to the high potential for failure. Despite this, successful screens for high-value protein targets such as Ab, Myc, and a-synuclein are present in the literature, [129][130][131][132][133][134] suggesting that screening is a viable strategy for the discovery of chemical tools and drug leads that target IDPs directly. 134 Rational structure-based design has also been challenging although there is now at least one example of a successful structure-activity relationship (SAR)-based campaign against IDPs in the literature.…”

“…Despite this, successful screens for high-value protein targets such as Ab, Myc, and a-synuclein are present in the literature, [129][130][131][132][133][134] suggesting that screening is a viable strategy for the discovery of chemical tools and drug leads that target IDPs directly. 134 Rational structure-based design has also been challenging although there is now at least one example of a successful structure-activity relationship (SAR)-based campaign against IDPs in the literature. 135 Given the central roles of IDPs and LLPS in cell biology and disease, the dearth of small-molecules capable of selectively engaging IDPs for use as chemical probes or therapeutic leads is an important problem in the eld and makes this area of research especially exciting.…”