Antibacterial and antifungal activity. Presents chitin-binding activity. Cytoplasmic granules of hemocytes and to a lesser extent in small granules of hemocytes. Strongly expressed in hemocytes, and to a lesser extent in heart, muscle, gills, intestine and eyestalk. Lowest expression in hepatopancreas. Highest expression at premolt stage and lower expression at postmolt and intermolt stages. Up-regulated in response to V.parahaemolyticys challenge. Highest expression at 6 hours postinjection of the bacterium, then gradually down-regulated upto 48 hours postinjection. The N-terminus forms pyrrolidone carboxylic acid. Belongs to the penaeidin family.