Host-defense peptide that has antimicrobial activity against Gram-negative bacteria, and to a lesser extent also against Gram-positive bacteria and fungi (By similarity). Exhibits antimicrobial activity against Gram-negative E.coli and E.aerogenes and Gram-positive S.faecalis, S.aureus and B.cereus and the yeast C.albicans (in vitro) (By similarity). Inhibits corticotropin (ACTH)-stimulated corticosterone production (in vitro) (By similarity). Inhibits enzymatic activity of B.anthracis lef/anthrax lethal factor (in vitro) (By similarity). Homodimer; homodimerization seems to be required for killing S.aureus, but not E.coli (By similarity). Interacts with CD4 (By similarity). Interacts with Bacillus anthracis lef; homodimerization is required for the interaction (By similarity). Stored as mature peptide in neutrophil granules. The three-dimensional structure formed by the three intramolecular disulfide bridges is indispensable for effective bacterial killing. Belongs to the alpha-defensin family.