Antimicrobial Activity of Native and Synthetic Surfactant Protein B Peptides

摘要: Surfactant protein B (SP-B) is secreted into the airspaces with surfactant phospholipids where it reduces surface tension and prevents alveolar collapse at end expiration. SP-B a member of saposin-like family proteins, several which have antimicrobial properties. lyses negatively charged liposomes was previously reported to inhibit growth Escherichia coli in vitro; however, separate study indicated that elevated levels transgenic mice did not confer resistance infection. The goal this assess properties native synthetic peptides derived from peptide. Native aggregated killed clinical isolates Klebsiella pneumoniae , Pseudomonas aeruginosa Staphylococcus aureus group streptococcus by increasing membrane permeability; also lysed RBC, indicating membranolytic activity selective for bacteria. Both hemolytic activities were inhibited phospholipids, suggesting endogenous may play significant role host defense. Synthetic effective killing both Gram-positive Gram-negative bacteria low peptide concentrations (0.15–5.0 μM). derivatives selectively bacterial membranes more resistant inhibition phospholipids; furthermore, helix 1 (residues 7–22) retained presence surfactant. These results suggest defense be limited; useful treatment pneumonias.