novel defensin-like peptide associated with two other new cationic antimicrobial peptides in transcriptome of the Iranian scorpion venom

Introduction: Scorpion venom is a source of bioactive peptides, and some antimicrobial peptides [AMPs] have been found in the venom gland of scorpions. Therefore, the discovery of new anti-infective agents is an essential need to overcome the problem of antibiotic resistance of clinical isolates. Here, we describe three new cationic AMPs, including meuVAP-6, meuAP-18-1, and meuPep34 from the venom gland of the Iranian scorpion, Mesobuthus eupeus

Methods: The cDNA sequences encoding all the three peptides were obtained from the cDNA library of scorpion venom gland and were deposited in the GenBank database

Results: MeuVAP-6 and meuAP-18-1 are non-disulphide-bridged antimicrobial peptides, while meuPep34 is a cysteine-rich defensin-like peptide

Discussion: All three identified AMPs are rich in arginine and tryptophan. The overall results from the length, net charge, and hydrophobicity index suggested that meuPep34 could be the most active AMPs with the potential ability of biofilm inhibition. The data from molecular characterization of identified AMPs can provide a platform for further investigations in the drug design

Molecular Characterization and Biodiversity of a Putative Chlorotoxin from the Iranian Yellow Scorpion Odontobuthus doriae

Background: Chloride channels have already been over-expressed in the different types of cancer. Chlorotoxins, as the blocking agent of these channels, have been indicated to be an effective drug against tumors. In this study, we characterized a putative chlorotoxin from a cDNA library of the venom glands obtained from the Iranian scorpion Odontobuthus doriae

Methods: A cDNA library was constructed from venom gland transcriptome of six scorpions. The cDNA encoding Odontobuthus doriae chlorotoxin was isolated from the library, and its putative peptide was characterized by some bioinformatics software such as protein blast, SignalP4.0, DISULFIND and Clustal Omega

Results: The mature Odontobuthus doriae chlorotoxin peptide has a 35-amino-acid residue and four disulfide bounds. This putative chlorotoxin is a small, compact, and stable molecule. Moreover, based on the open reading frame sequence similarity, this peptide is similar to Buthus martensii Karsch chlorotoxin-like toxin and Bml2-b neurotoxins from the Chinese scorpion Mesobuthus martensii

Conclusion: The small size of this putative chlorotoxin and its stability make it as a suitable candidate for medical and pharmacological research, especially in the cancer research