Human Peptidase Inhibitor 16/PI16 Antibody

PI16 (Peptidase Inhibitor 16; also PSP94-binding protein) is a 70‑75 kDa member of the CRISP family of proteins. It is expressed by prostatic fibroblasts and cardiomyocytes and is known to bind PSP94. The human PI16 precursor is 463 amino acids (aa) in length. It contains a 27 aa signal peptide plus a 436 aa mature region. The mature region has been described as being either a type I transmembrane (TM) glycoprotein with a TM segment between aa 443‑462, or a GPI‑linked glycoprotein with C‑terminal cleavage between Lys437‑Asn438. Three potential variants exist. One shows a deletion of aa 231‑423, a second shows a 9 aa substitution for the C‑terminal 64 aa and a third shows a 43 aa insertion after Cys197. Over aa 28‑437, human PI16 is 67% aa identical to mouse PI16.