Host defense peptide that exhibits antimicrobial activity against both Gram-negative bacteria, such as E.coli and S.typhimurium, and Gram-positive bacteria, such as S.aureus and B.subtilis (By similarity). Inhibits cell adhesion of E.coli on intestinal epithelial enterocytes (By similarity). Causes rapid permeabilization of both the outer and inner membrane of E.coli, leading to morphological alterations on the bacterial surface (By similarity). Binds to bacterial lipopolysaccharides (LPS) with high affinity, and may thereby be involved in immunoregulation through LPS neutralization (By similarity). May contribute to epididymal innate immunity and protect the sperm against attack by microorganisms (By similarity). The three-dimensional structure formed by the three intramolecular disulfide bridges is indispensable for antimicrobial activity. Belongs to the beta-defensin family.