Has broad-spectrum antimicrobial properties (PubMed:17620056, PubMed:19211153). The antimicrobial activity decreases in the present of salt in vitro (PubMed:19211153). Binds anionic phospholipids, which leads to the aggregation of liposomes in vitro (PubMed:25769951). Membrane permeabilization of the target cells is an essential part of the peptide's mode of antimicrobial activity (PubMed:17620056, PubMed:22232283). No hemolytic activity against sheep or horse erythrocytes (PubMed:22232283). Has antibacterial activity against the bacterial horse pathogens Gram-positive R.equi ATCC 33701 P(-) (minimum bactericidal concentration or MBC=5 ug/ml) and R.equi ATCC 33701 P(+) (MBC=5 ug/ml), which are resistant against beta-lactam antibiotics. Also has antibacterial activity against highly infectious wild-type strain R.equi 85F P(+) (MBC=5 ug/ml), S.equi subsp. equi (MBC=5 ug/ml), S.equi subsp. zooepidemicus (MBC=5 ug/ml), S.dysgalactiae subsp. equisimilis (MBC=10 ug/ml), S.choleraesuis subsp. choleraesuis serovar Typhimurium (MBC=10 ug/ml), and P.multocida subsp. multocida (MBC=>10 ug/ml) (PubMed:19211153). Probably contributes to the antimicrobial barrier function of the small bowel mucosa (Probable). Paneth cells of the small bowel. Belongs to the alpha-defensin family.