Responsible for the proteolytic processing of the amyloid precursor protein (APP). Cleaves APP, between residues 690 and 691, leading to the generation and extracellular release of beta-cleaved soluble APP, and a corresponding cell-associated C-terminal fragment which is later released by gamma-secretase. It has also been shown that it can cleave APP between residues 671 and 672. Responsible also for the proteolytic processing of CLTRN in pancreatic beta cells (PubMed:21907142). Broad endopeptidase specificity. Cleaves Glu-Val-Asn-Leu-|-Asp-Ala-Glu-Phe in the Swedish variant of Alzheimer's amyloid precursor protein. Monomer. Interacts ith RTN3 and RTN4. Brain. Present in neurons within the hippocampus, frontal cortex and temporal cortex (at protein level). Expressed at low levels in most peripheral tissues and at higher levels in colon, kidney, pancreas, placenta, prostate, stomach and trachea. Expressed at low levels in the brain. Found in spinal cord, medulla oblongata, substantia nigra and locus coruleus. Expressed in the ductal epithelium of both normal and malignant prostate. Up-regulated in primary breast and colon tumors and liver metastasis. Undergoes autoproteolytic cleavage. Glycosylated. Belongs to the peptidase A1 family.