Neurodegeneration in Parkinson's disease (PD) is closely associated with the accumulation of α- synuclein (α-syn) protein aggregates known as Lewy bodies. Understanding the diverse conformations adopted by α-syn in both healthy and diseased states is crucial for developing effective interventions. Recent advances in structural biology have provided valuable insights into the structural diversity of α- syn amyloid fibrils. However, the extent to which these in vitro models represent the conformations amplified in biological settings remains uncertain. This uncertainty hinders our ability to develop tools like PET-tracers, small molecules that bind to amyloid fibrils that can be used to localize and monitor disease progression in vivo. This project aims to bridge this gap by determining if the amyloid conformations that can be propagated in vitro can be propagated inside cells. To do so, we will leverage the sensitivity gains of dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) spectroscopy to investigate the conformations of α-syn fibrils amplified inside cells and compare them with in vitro amplified fibrils. By using biosensor cell lines capable of propagating α-syn amyloid conformations, we will examine the structural features of α-syn fibrils in cellular environments. This knowledge will facilitate the optimization of in silico structure-based and chemical screens to identify selective α-syn ligands.