Brigita Urbanc

Amyloid β-protein (Aβ) is believed to cause Alzheimer’s disease (AD); this belief is based largely on studies showing autosomal dominant inheritance of familial AD (FAD) due to mutations that increase brain concentration levels of Aβ or of particular forms of Aβ. However, how specifically this leads to AD is not clear. Several mutations have been identified inside the Aβ-coding region of the amyloid β protein precursor (APP); these mutations change both the biophysical characteristics of Aβ and the disease phenotype, such as age of onset of dementia and location and morphology of amyloid deposits. Characterizing the effects of the amino acid changes in Aβ on the protein’s assembly and toxicity may help to identify Aβ regions particularly useful as drug targets. We summarize here key findings related to substitutions at positions 2, 6, 7, 16, 21–23, and 34 in Aβ and their relation to FAD.