Antibacterial peptide mostly active against Gram-positive bacteria. Has activity against the bacteria Gram-negative E.cloacae beta12. Expressed 75 minutes after bacterial infection. Increased dramatically after 6 hours, continued to increase through to 24 hours and is maintained at high levels until at least 30 hours after bacterial infection. By bacterial infection. There are five defensin A forms, A1 (shown here) A2, A3, A4 and A5. Belongs to the invertebrate defensin family. Type 1 subfamily.