Inhibitor and substrate cooperate to inhibit amyloid fibril elongation of α-synuclein

Abstract

In amyloid fibril elongation, soluble growth substrate binds to the fibril-end and converts into the fibril conformation. This process is targeted by inhibitors that block fibril-ends. Here, we investigated how...

Rationally Designed Protein-Based Inhibitor of α-Synuclein Fibrillization in Cells

“…This perturbs the binding interface for the further αSyn molecules and thus prevents fibril growth because αSyn molecules cannot form the same hydrogen bonds as upon binding to unmodified fibril (Figure 3A). A similar mechanism of action was reported for inhibitors based on αSyn dimers 32,39 that bind to the fibril end in an altered conformation perturbing binding of further αSyn molecules.…”

“…As a result, the T 1 R 2 inhibitor is 10-fold more efficient than T 1 T 2 and R 1 R 2 , which only alter the binding site (Figure 1C). Moreover, T 1 R 2 is much smaller (≈9.5 kDa) than αSyn conjugates or dimer-based inhibitors (∼28 kDa) 32,34,39 Its monocysteine mutant form, T 1 R 2 -E84C, shows IC 50 ≈ 5−10 nM at 50 μM αSyn overperforming the best known inhibitor to date, the conjugate of αSyn with its dicysteine mutant (WT-CC48). 32 Selectivity and Activity in Cells.…”

“…Moreover, T 1 R 2 is much smaller (≈9.5 kDa) than αSyn conjugates or dimer-based inhibitors (∼28 kDa) 32,34,39 Its monocysteine mutant form, T 1 R 2 -E84C, shows IC 50 ≈ 5−10 nM at 50 μM αSyn overperforming the best known inhibitor to date, the conjugate of αSyn with its dicysteine mutant (WT-CC48). 32 Selectivity and Activity in Cells. The inhibitors presented in this work are based on the αSyn sequence, and therefore will preferentially bind to αSyn fibrils even in the presence of native cellular proteins rich in β-sheets.…”

“…Currently, several approaches of prevention of αSyn misfolding and toxicity have been developed: , modulation of αSyn expression, stimulation of protein degradation system, stabilization of the monomeric form of αSyn, , redirection of the aggregation to nontoxic oligomers, , clearance of misfolded species using antibodies, destabilization of αSyn fibrils, − and blocking fibril growth centers (late oligomers or fibril ends − ). Because the approaches targeting monomeric αSyn can perturb its physiological functions, selective targeting of pathological species is preferable.…”

Molecular Mechanisms of Inhibition of Protein Amyloid Fibril Formation: Evidence and Perspectives Based on Kinetic Models

“…In order to inhibit α-synuclein aggregation, a chimeric inhibitor comprising a globular protein with 41.5 kDa molecular weight fused to the C-terminus of the α-synuclein monomer has been developed [ 188 ]. α-synuclein, with a preformed hairpin between cysteine residues, was also shown to inhibit the wild-type synuclein fibril elongation [ 189 ]. When the modified and wild-type proteins were fused, a much more potent inhibitor was obtained.…”