Serase-1 and serase-2 are serine proteases that hydrolyze the peptides N-t-Boc-Gln-Ala-Arg-AMC and N-t-Boc-Gln-Gly-Arg-AMC. In contrast, N-t-Boc-Ala-Phe-Lys-AMC and N-t-Boc-Ala-Pro-Ala-AMC are not significantly hydrolyzed (By similarity). Inhibited by serine protease inhibitors PMSF and 4-(2-aminoethyl)benzenesulfonyl fluoride, but not by EDTA. The serine protease 1 and 2 domains are catalytically active, whereas the serine protease 3 domain lacks the essential Ser residue of the catalytic triad at position 1015 and is predicted to be inactive. Proteolytically cleaved to generate 3 independent serine protease chains. The cleaved chains may remain attached to the membrane thanks to disulfide bonds. It is unclear whether cleavage always takes place (By similarity). Belongs to the peptidase S1 family.