A novel cysteine-free venom peptide with strong antimicrobial activity against antibiotics-resistant pathogens from the scorpion Opistophthalmus glabrifrons

• Published in: Journal of peptide science Vol. 21; no. 10; pp. 758 - 764
• Main Authors: Bao, Aorigele, Zhong, Jie, Zeng, Xian-Chun, Nie, Yao, Zhang, Lei, Peng, Zhao Feng
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.10.2015; Wiley Subscription Services, Inc
• Subjects: Animals; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Anti-Infective Agents - pharmacology; antibiotic-resistant bacteria; antimicrobial peptide; Cysteine - chemistry; Drug Resistance, Bacterial; Enterococcus; Gram-Negative Bacteria - drug effects; Gram-Positive Bacteria - drug effects; methicillin-resistant Staphylococcus aureus (MRSA); Microbial Sensitivity Tests; Molecular Sequence Data; Opistophthalmus glabrifrons; Peptides; scorpion; Scorpion Venoms - chemistry; Scorpions - microbiology; Staphylococcus aureus; vancomycin-resistant Enterococcus (VRE); Opistophthalmus glabrifrons; vancomycin-resistant Enterococcus (VRE); antimicrobial peptide; methicillin-resistant Staphylococcus aureus (MRSA); antibiotic-resistant bacteria; scorpion
• ISSN: 1075-2617; 1099-1387
• DOI: 10.1002/psc.2801

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. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd. A novel antimicrobial peptide, referred to as Opisin, was discovered from the scorpion Opistophthalmus glabrifrons. Opisin possesses strong antimicrobial activity against antibiotics‐resistant pathogens, such as methicillin‐resistant Staphylococcus aureus (MRSA) and vancomycin‐resistant Enterococcus (VRE). This suggests that Opisin has great potential for the treatment of infections caused by MRSA and VRE.