Amyloid precursor protein (APP) is precursor protein of Amyloid β which is major constituent of senile plaque in Alzheimer’s disease. It is known that there are three major isoforms, APP695, APP751 and APP770, and are generated from alternative splicing of common precursor mRNA.
Amyloid β (Aβ; which is major constituent of senile plaque) is cleaved from Amyloid Precursor Protein (APP; which exists in three main isoforms, APP695, APP751, and APP770) by β-secretase and subsequent γ-secretase (ref. 1). The production of soluble APPβ (sAPPβ) by β-secretase cleavage corresponds to Aβ production accordingly, so it is desired to measure sAPPβ in parallel with Aβ.