title: Identification and biochemical characterization of a new antibacterial and antifungal peptide derived from the insect Sphodromantis viridis.
abstract: Antimicrobial peptides are members of the immune system that protect the host from infection. In this study, a potent and structurally novel antimicrobial peptide was isolated and characterized from praying mantis Sphodromantis viridis. This 14-amino acid peptide was purified by RP-HPLC. Tandem mass spectrometry was used for sequencing this peptide, and the results showed that the peptide belongs to the Mastoparan family. The peptide was named Mastoparan-S. Mastoparan-S demonstrated that it has antimicrobial activities against a broad spectrum of microorganisms (Gram-positive and Gram-negative bacteria and fungi), and it was found to be more potent than common antibiotics such as kanamycin. Mastoparan-S showed higher antimicrobial activity against Gram-negative bacteria compared to Gram-positive ones and fungi. The minimum inhibitory concentration (MIC) values of Mastoparan-S are 15.1-28.3 µg/ml for bacterial and 19.3-24.6 µg/ml for fungal pathogens. In addition, this newly described peptide showed low hemolytic activity against human red blood cells. The in vitro cytotoxicity of Mastoparan-S was also evaluated on monolayer of normal human cells (HeLa) by MTT assay, and the results illustrated that Mastoparan-S had significant cytotoxicity at concentrations higher than 40 µg/ml and had no any cytotoxicity at the MIC (≤30 µg/ml). The findings of the present study reveal that this newly described peptide can be introduced as an appropriate candidate for treatment of topical infection.
authors: Young Researchers and Elite Club, Yazd Branch, Islamic Azad University, Yazd, Iran.
authors: Hadi
authors: H
authors: Zare-Zardini
authors: Asghar
authors: A
authors: Taheri-Kafrani
authors: Mahtab
authors: M
authors: Ordooei
authors: Leila
authors: L
authors: Ebrahimi
authors: Behnaz
authors: B
authors: Tolueinia
authors: Mojgan
authors: M
authors: Soleimanizadeh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D020050:Mantodea / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010802:Phylogeny; D020539:Sequence Analysis, Protein
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D019476:Insect Proteins; C000603952:mastoparan S, Sphodromantis viridis