A novel antimicrobial peptide from skin secretions of the earthworm, Pheretima guillelmi (Michaelsen)

A novel lumbricin-like antimicrobial peptide named lumbricin-PG was isolated from skin secretions of the earthworm, Pheretima guillelmi (Michaelsen), using a procedure of one step Sephadex G-50 gel filtration and one step C8 reverse-phase high-performance liquid chromatography (RP-HPLC). Its amino acid sequence was determined as FSRYARMRDSRPWSDRKNNYSGPQFTYPPEKAPPEKLIKWNN EGSPIFEMPAEGGHIEP by Edman degradation combined with cDNA cloning and mass spectrometry analysis. The cDNA encoding lumbricin-PG was cloned by cDNA library screening. The predicted protein from the cDNA sequence was composed of 73 amino acid residues including a mature lumbricin-PG and predicted signal peptide. It showed similarity with lumbricin antimicrobial peptide from the earthworm, Lumbricus rubellus by BLAST search. Purified lumbricin-PG exerted potential antimicrobial activities against bacteria and fungi; it showed weak hemolysis activity against human and rabbit red cells.

► A novel lumbricin-like antimicrobial peptide named lumbricin-PG was isolated from skin secretions of the earthworm, P. guillelmi.
► Its amino acid sequence was determined as FSRYARMRDSRPWSDRKNNYSGPQFTYPPEKAPPEKLIKWNNEGSPIFEMPAEGGHIEP.
► The predicted protein from the cDNA sequence was composed of 73 amino acid residues including a mature lumbricin-PG and predicted signal peptide.
► Purified lumbricin-PG exerted potential antimicrobial activities against bacteria and fungi; it showed weak hemolysis activity against human and rabbit red cells.