TPPII(Tripeptidyl-peptidase 2) is an evolutionary conserved serine peptidase of the subtilisin family that removes tripeptides from the free NH2 terminus of oligopeptides. The 138-kDa TPP2 polypeptide forms large oligomeric complexes of >1,000 kDa that are detected in the cytoplasm of all cell types. In addition,a membrane associated TPP 2 isoform is present in most cells.