title: A novel cysteine-free venom peptide with strong antimicrobial activity against antibiotics-resistant pathogens from the scorpion Opistophthalmus glabrifrons.
abstract: Antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, pose serious threat to human health. The outbreak of antibiotic-resistant pathogens in recent years emphasizes once again the urgent need for the development of new antimicrobial agents. Here, we discovered a novel antimicrobial peptide from the scorpion Opistophthalmus glabrifrons, which was referred to as Opisin. Opisin consists of 19 amino acid residues without disulfide bridges. It is a cationic, amphipathic, and α-helical molecule. Protein sequence homology search revealed that Opisin shares 42.1-5.3% sequence identities to the 17/18-mer antimicrobial peptides from scorpions. Antimicrobial assay showed that Opisin is able to potently inhibit the growth of the tested Gram-positive bacteria with the minimal inhibitory concentration (MIC) values of 4.0-10.0 μM; in contrast, it possesses much lower activity against the tested Gram-negative bacteria and a fungus. It is interesting to see that Opisin is able to strongly inhibit the growth of methicillin- and vancomycin-resistant pathogens with the MICs ranging from 2.0 to 4.0 μM and from 4.0 to 6.0 μM, respectively. We found that at a concentration of 5 × MIC, Opisin completely killed all the cultured methicillin-resistant Staphylococcus aureus. These results suggest that Opisin is a promising therapeutic candidate for the treatment of the antibiotic-resistant bacterial infections.
authors.affiliation: Department of Biological Science and Technology, School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
authors.forename: Aorigele
authors.initials: A
authors.lastname: Bao
authors.affiliation: Department of Biological Science and Technology, School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Department of Biological Science and Technology, School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
authors.forename: Xian-Chun
authors.initials: XC
authors.lastname: Zeng
authors.affiliation: Department of Biological Science and Technology, School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Nie
authors.affiliation: Department of Biological Science and Technology, School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Biological Science and Technology, School of Environmental Studies, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
authors.forename: Zhao Feng
authors.initials: ZF
authors.lastname: Peng
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D003545:Cysteine / Q000737:chemistry*; D024881:Drug Resistance, Bacterial; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D012604:Scorpion Venoms / Q000737:chemistry; D012605:Scorpions / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D012604:Scorpion Venoms; D003545:Cysteine
keywords: Opistophthalmus glabrifrons; antibiotic-resistant bacteria; antimicrobial peptide; methicillin-resistant Staphylococcus aureus (MRSA); scorpion; vancomycin-resistant Enterococcus (VRE)