THE MOLECULAR-BASIS OF AMYLOIDOSIS

Amyloidoses are diseases, including some currently prominent such as A lzheimer's disease, bovine spongiform encephalophaty (BSE) and Type II diabetes, in which soluble proteins are deposited in a specific, high ly stable, fibrillar form. The amyloid fibrils are made up of protofil aments whose molecular structure is composed of pairs of beta-sheets i n a helical form that allows them to be continuously hydrogen-bonded a long the length of the fibril. The observation that similar fibrils ar e generated from different proteins indicates that fibril formation is accompanied by structural conversion. The transmissible spongiform en cephalopathies, such as BSE and kuru, involve an infectious agent iden tified with the prion protein. The properties of the agent are more co nsistent with prion amyloid than the protein itself, suggesting infect ivity in these diseases is equivalent to the 'seeding' of amyloid fibr ils at a new site.