[3] Amyloid beta (Aβ) is composed of a family of peptides produced by proteolytic cleavage of the type I transmembrane spanning glycoprotein amyloid-beta precursor protein (APP).
Amyloid plaque Aβ protein species ends in residue 40 or 42,[4] but it is suspected that Aβ42 form is crucial in the pathogenesis of AD.
Most β-secretase activity originates from an integral membrane aspartyle protease encoded by the β-site APP-cleaving enzyme 1 gene (BACE1).
[8] APP is an integral membrane protein whose proteolysis generates beta amyloid ranging from 39- to 42- amino acid peptide.
Recent research has shown that large soluble APP (sAPP)[9] that are present in CSF may serve as a novel potential biomarker of Alzheimer's disease.
Although many researchers have found that the CSF level of α sAPP increases in some people with AD, some report that there is no significant change, while Lannfelt argues that there is a slight decrease.
Therefore, more studies using experimental models are needed in order to confirm the validity of sAPP as a biological marker for AD.
In order to avoid provide solution for discrepancy in the existing data, Dr. Gustaw came up with novel method of dissociation sample.
The dissociated sample results show significant increases in AD patients, which contradicts the majority of previous studies.
An open international study group (ND.Neuromark.net) has been constituted for arranging scientific information and developing a rational guide for implementing biomarkers into routine practice.