A central pathological feature of Alzheimers disease (AD) is the accumulation of misfolded amyloid beta (Abeta) peptides in the form of oligomers and amyloid fibrils in the brain. Substitution of a single amino acid in the sequence of Abeta as a result of genetic defects may either trigger a rapid disease development or, on the contrary, produce a protective effect. Molecular mechanisms underlying these effects are still unclear. X-ray (XRD) and neutron diffraction (ND) from the assemblies, formed by various biologically relevant Abeta mutants, provide information about structural features of amyloid assemblies at the molecular level, and may help to answer this question. Our recent small-angle ND studies clearly demonstrated the differences between structural organization of fibers formed by the wild type Abeta and its highly fibrillogenic form carrying an Ala-to-Val substitution at position two. In this study we will: 1) complement the small-angle ND patterns data with high-angle scattering data; 2) record and compare ND patterns from various Abeta analogues that produce disease triggering or protective effects.