Proteins are essential for organisms and participate in virtually every process within cells. Knowledge about the structure of proteins provides crucial information about their function in... Show moreProteins are essential for organisms and participate in virtually every process within cells. Knowledge about the structure of proteins provides crucial information about their function in biological mechanisms. In determining the structure of proteins with biophysical approaches, electron paramagnetic resonance (EPR) is rapidly gaining ground. The aim of this thesis is to provide insight in how broad the application of EPR can be to study proteins, in particular those which are difficult if not impossible to study with other approaches. The focus of this thesis is to investigate the aggregation and misfolding of intrinsically disordered proteins and to determine the structure of disordered parts of proteins with EPR. Specifically, the amyloid β (Aβ) peptide, the α-synuclein (αS) protein, and the light-harvesting protein CP29 are studied. Show less