[Antimicrobial proteins of insect and their clinical application].

We isolated three antimicrobial proteins from the hemolymph of immunized Sarcophaga peregrina (flesh fly) larvae. These are sarcotoxin I, sapecin and antifungal protein (AFP). Sarcotoxin I and sapecin are highly specific for Gram-negative and Gram-positive bacteria, respectively. AFP was found to have fungicidal activity. Primary target for these antimicrobial proteins was assumed to be microbial membrane. We were able to identify a core undecapeptide of sapecin B. We modified this peptide and finally obtained KLKLLLLLKLK-NH2 and its D-enantiomer. These peptides were effective against various bacteria including MRSA. We found that MRSA-infected mine are cured by treating with these peptides.