APP map     Ab MAP

Production of Abeta

Different beta and gamma secretase activities are able to release different types of Abeta peptides.

Some peptide are increased in familial Alzheimer's disease, and more specifically 1-42(43) Abeta.The ration 42/40 is increased.

Abeta is also truncated or ragged in part at the N-terminal site of the beta clivage site, giving x-40 and x-42 aminoacids. N-truncated Ab 42 species are the germs of amyloid

A secondary physiological cleavage at the b' site (see figure) is also occuring.