Beta-amyloid production results from cleavage in the extracellular domain of APP by the beta-secretase (BACE1) , which results in the production of the APP C-terminal fragment C99. This fragment is further cleaved by the gamma-secretase at residues 40-42 to produce beta-amyloid 40 and 42 peptides. Beta-amyloid aggregation and neuritic plaque formation are pathologic hallmarks of Alzheimer disease. This peptide corresponds to the human beta-amyloid 1-40 peptide.Human: 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