Single-Molecule FRET Detection of Early-Stage Conformations in α-Synuclein Aggregation

: Misfolding and aggregation of α-synuclein are linked to many neurodegenerative disorders, including Parkinson's and Alzheimer's disease. Despite intense research efforts, detailed structural characterization of early conformational transitions that initiate and drive α-synuclein aggregation remains elusive often due to the low sensitivity and ensemble averaging of commonly used techniques. Single-molecule Forster resonance energy transfer (smFRET) provides unique advantages in detecting minor conformations that initiate protein pathologic aggregation. In this chapter, we describe an smFRET-based method for characterizing early conformational conversions that are responsible for α-synuclein self-assembly and aggregation.