amyloid beta precursor protein alpha-sAPP peptidase nexin-II Alzheimer disease amyloid beta (A4) precursor protein AAA ABETA ABPP AD1 APPI CTFgamma CVAP PN-II PN2 preA4 amyloid-beta precursor protein alzheimer disease amyloid A4 protein homolog alzheimer disease amyloid protein amyloid beta A4 protein amyloid precursor protein beta-amyloid peptide beta-amyloid peptide(1-40) beta-amyloid peptide(1-42) beta-amyloid precursor protein cerebral vascular amyloid peptide protease nexin-II testicular tissue protein Li 2 A4 Amyloid-beta precursor protein Alzheimer disease amyloid A4 protein homolog Alzheimer disease amyloid protein Amyloid precursor protein Amyloid-beta (A4) precursor protein Amyloid-beta A4 protein Cerebral vascular amyloid peptide PreA4 Protease nexin-II