Serine protease. May be involved in the invasion of grains and hydrolyzation of grain proteins. Inhibited by phenylmethanesulfonyl fluoride (PMSF) and chymostatin (CST), but not by Bowman-Birk type trypsin-chymotrypsin inhibitor (BBI). Optimum pH is 8.3-9.6. Optimum temperature is 40 degrees Celsius. By gluten. Belongs to the peptidase S8 family.