Amyloid precursor protein




Amyloid precursor protein (APP) is an integral membrane protein expressed in many tissues and concentrated in the synapses of neurons. Its primary function is not known, though it has been implicated as a regulator of synapse formation, neural plasticity and iron export. APP is best known as the precursor molecule whose proteolysis generates beta amyloid (Aβ), a polypeptide containing 37 to 49 amino acid residues whose amyloid fibrillar form is the primary component of amyloid plaques found in the brains of Alzheimer's disease patients.