A novel antimicrobial peptide, scolopendin, from Scolopendra subspinipes mutilans and its microbicidal mechanism.
A novel antimicrobial peptide (AMP) was identified from the centipede Scolopendra subspinipes mutilans by RNA sequencing, and the amino acid sequences predicted from the sequenced mRNAs were compared with those of known AMPs. We named this peptide scolopendin, according to its origin, and investigated the molecular mechanisms underlying its antimicrobial activity. Our findings showed that scolopendin had antimicrobial activity against several pathogenic microorganisms, but did not produce hemolysis of human erythrocytes. In addition, disturbances in the cell membrane potential, induction of potassium release from the cytosol, and increased membrane permeability of the microbes Candida albicans and Escherichia coli O157 were detected by the use of 3,3'-dipropylthiacarbocyanine iodide [DiSC3(5)] dye, potassium leakage assay, and propidium iodide influx assay, respectively, following scolopendin treatment. Further evidence to support the membrane-targeted action of scolopendin was obtained using artificial liposomes as models of the cell membrane. Use of calcein and FITC-labeled dextran leakage assays from scolopendin-treated giant unilamellar vesicles and large unilamellar vesicles showed that scolopendin has a pore-forming action on microbial membrane, with an estimated pore radius of 2.3-3.3 nm. In conclusion, scolopendin is a novel and potent AMP with a membrane-targeted mechanism of action.
School of Life Sciences, BK 21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daehak-ro 80, Buk-gu, Daegu, 702-701, Republic of Korea.
Wonyoung
W
Lee
Department of Agricultural Biology, National Academy of Agricultural Science, RDA, Jeonju, Republic of Korea.
Jae-Sam
JS
Hwang
School of Life Sciences, BK 21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daehak-ro 80, Buk-gu, Daegu, 702-701, Republic of Korea. Electronic address: dglee222@knu.ac.kr.
Dong Gun
DG
Lee
D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D060829:Arthropod Proteins / Q000494:pharmacology*; D001181:Arthropods; D002463:Cell Membrane Permeability / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins
Antimicrobial effect; Antimicrobial peptide; Plasma membrane; Scolopendin; Scolopendra subspinipes mutilans