A number of Aß protein variants, differing only at their carboxy terminus (1-39, 1-40, 1-42 and 1-43), are identified as the major components of the cerebral amyloid deposits in Alzheimer’s disease. The length of the C-terminus is a critical determinant of the rate of amyloid formation (“kinetic solubility”), with only a minor effect on the thermodynamic solubility. Amyloid formation by the kinetically soluble peptides (e.g. 1-41) can be nucleated, or “seeded” by peptides which include the critical C-terminal residues (1-42, 26-42, 26-43, 34-42).
H - Asp - Ala - Glu - Phe - Arg - His - Asp - Ser - Gly - Tyr - Glu - Val - His - His - Gln - Lys - Leu - Val - Phe - Phe - Ala - Glu - Asp - Val - Gly - Ser - Asn - Lys - Gly - Ala - Ile - Ile - Gly - Leu - Met - Val - Gly - Gly - Val - Val - Ile - OH