Lysine-specific molecular tweezers are broad-spectrum inhibitors of assembly and toxicity of amyloid proteins

Amyloidoses are diseases characterized by abnormal protein folding and self-assembly, for which no cure is available. Inhibition or modulation of abnormal protein self-assembly, therefore, is an attractive strategy for prevention and treatment of amyloidoses. We examined Lys-specific molecular tweezers and discovered a lead compound termed CLR01, which is capable of inhibiting the aggregation and toxicity of multiple amyloidogenic proteins by binding to Lys residues and disrupting hydrophobic and electrostatic interactions important for nucleation, oligomerization, and fibril elongation. Importantly, CLR01 shows no toxicity at concentrations substantially higher than those needed for inhibition. We used amyloid β-protein (Aβ) to further explore the binding site(s) of CLR01 and the impact of its binding on the assembly process. Mass spectrometry and solution-state NMR demonstrated binding of CLR01 to the Lys residues in Aβ at the earliest stages of assembly. The resulting complexes were indistinguishable i...