The most stable conformation of proteins is the cross-β structure, which is a common feature of all amyloid fibrils. These protein aggregates may have pathologic consequences, as for example in Alzheimer’s disease, or function as biologically relevant form of the protein. Amyloid proteins share a common cross-β structure as well as a similar morphology even though they contain a very different primary amino acid sequence. A large body of scientific research on this topic has not been able so far to fully explain the formation of amyloid fibrils on a molecular level. In this thesis three protein model systems have been investigated in order to derive generic characteristics of the fibrillation process as well as its comprehension on a molecular level: The β amyloid peptide involved in Alzheimer’s disease, the serum amyloid A 1.1 and the human parathyroid hormone PTH(1-84). To address this subject, a variety of different high resolution NMR methods have been applied.