PGC, also known as gastricsin, is an aspartic proteinase that belongs to the peptidase family A1. It is synthesized in the gastric mucosa as inactive precursors. It contains a prosegment that serves to stabilize the inactive form and prevent entry of the substrate to the active site. Serum levels of PGC are used as a biomarker for certain gastric diseases including Helicobacter pylori related gastritis. Recombinant human PGC, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques