Alpha secretase

Alpha- secretases are a family of proteolytic ( protein -degrading ) enzyme, and thus a subset of the peptidases or proteases. One of the functions of the alpha - secretases is the cleavage of the membrane protein APP ( amyloid precursor protein ) in a region that is partly inside and partly on the outer side or the extracellular side of the membrane and is thus called the transmembrane region. The cleavage site of the APP is referred to as Aβ ( amyloid β ) because of it taking part in the development of Alzheimer's beta -amyloid peptide is produced when it is cleaved by beta - and gamma -secretase. Therefore, the cleavage of APP by alpha -secretase inhibits the formation of β -amyloid peptide, and thus the development of Alzheimer's disease. The resulting water-soluble product sAPP ( secreted APP) or APPsα has neuroprotective ( nervenzellen protective) functions. The fission process of APP by alpha - secretase is known as ectodomain shedding.

Alpha - secretases belonging to the ADAM protein family (a disintegrin and metalloprotease domain). These are expressed on the cell surface and are anchored in the cell membrane. Other members of this family have been identified as alpha - secretases, including ADAM10, ADAM17 (also TACE, tumor necrosis factor - α converting enzyme ), ADAM9 and ADAM19.

The activity of alpha- secretases is awarded an influence in the control of learning and memory formation. The release of APPsα has neurotrophic effects that counteract apoptosis and promote the formation of new synapses.