Internal repeats of prion protein and A beta PP, and reciprocal similarity with the amyloid-related proteins.

We are currently interested in a group of proteins associated with the dementias characterized by amyloid deposition in the brain: amyloid beta protein precursor (A beta PP) of Alzheimer's disease (AD) and the abnormal isoform of prion protein (PrP) of spongiform encephalopathies such as kuru, Creutzfeldt-Jacob disease (CJD) and Gerstmann-Straussler-Scheinker disease (GSSD). Here we show that both A beta PP and prion protein (PrP) consist of peculiar internal repeats and share regions of sequence similarity. Further analysis revealed that local homology is also shared with the other proteins involved in specific forms of amyloidosis--i.e., the amyloid related proteins (ARP).