Table 1.

Features of selected Aβ-degrading enzymes.

Protease	a.k.a.	Class	Subcellular location	Substrates in addition to Aβ
Neprilysin	CD10, CALLA, EC 3.4.24.15	M	Cellular & intracellular membrane including presynaptic membrane	Enkephalin, cholecystokinin, neuropeptide Y, substance P, opiod peptides, atrial natriuretic peptides, bombesin-like peptides, chemotatic peptides, adrenocorticotropin homone (ACTH)
Insulin-degrading enzyme	EC 3.4.24.56 Insulysin, IDE	M	Cytosol, cellular, and intracellular membrane extracellular space	Insulin, glucagon, atrial natriuretic factor, β-endophin amylin, APP intracellular domain TGFα
Endothelin-converting enzyme	EC 3.4.24.71	M	Trans-Golgi network	Big endothelin, substance P, bradykinin, oxidized insulin B chain
	ECE		cell surface
Angiotensin-converting enzyme	EC 3.4.15.1; ACE; dipeptidyl carboxypeptidase	M	plasma membranes	Angitensin-I, enkaphalins, bradykinin
			perinuclear region
Plasmin/uPA/tPA	EC 3.4.21.31 tissue plasminogen activator for tPA; urokinase-type plasminogen activator for uPA	S	Extracellular space	fibrin, plasminogon, & other matrix proteins

Note: a.k.a. is also known as M: metalloproteases and S: serine.