Residue-Specific Fluorescent Probes of α-Synuclein: Detection of Early Events at the N- and C-Termini during Fibril Assembly

摘要

In the Parkinson’s disease-associated state,nR-synuclein undergoes large conformational changes, form-ning ordered, β-sheet-containing fibrils. To unravel the rolenof specific residues during the fibril assembly process, wenprepared single-Cys mutants in the disordered (G7C andnY136C) and proximal (V26Cand L100C) fibril core sites andnderivatized themwith environmentally sensitive dansyl (Dns)nfluorophores. Dns fluorescence exhibits residue specificity innspectroscopic properties as well as kinetic behavior; earlynkinetic events were revealed by probes located at positions 7nand 136 compared to those at positions 26 and 100