Fibroblast activation protein alpha (FAPa) is a type II transmembrane serine protease. It is present as a homodimeric integral protein with dipeptidyl peptidase IV like fold. It has an α/β-hydrolase domain and an eight-bladed β-propeller domain. It is not expressed in normal tissue. It is only expressed by activated fibroblast in response to pathologic situations. It is expressed in several pathogenic sites including cancer, fibrosis, arthritis, wounding, or inflammation.

FAPa may be used to study the role in coordinating the stromal response to cancer, in angiogenesis, and modulation of the antitumor immune response.

FAP is a Type II transmembrane serine protease which has substrate specificity for prolyl peptides bonds (Pro-Xaa). This endopeptidase cleaves gelatin and is believed to play a role in tissue remodeling, tumor invasion, and wound repair.

FAPα has in vitro dipeptidyl peptidase activity and collagenolytic activity. It cleaves N-terminal dipeptides from polypeptides and can degrade gelatin and type I collagen. It has also been reported that FAPa has a tumor suppressor activity.

Supplied as a solution in 25 mM Tris, 0.25 M NaCl and 20% (v/v) glycerol , pH 8.0

One unit will convert 1 picomole of benzyloxycarbonyl-Gly-Pro-7-amido-4-methylcoumarin (ZP-AMC) to Z-gly-Pro and 7-amino-4-methylcoumarin (AMC) per minute at pH 7.5 at 25°C.