Transcriptome analysis of a scorpion venom gland revealed the presence of a beta-toxin, a potent bioinsecticide.
Transcriptome analysis of a scorpion venom gland revealed the presence of a beta-toxin, a potent bioinsecticide.
Niloofar Chamanrou,1Masoumeh Baradaran,2,*Hamid galehdari,3Behnaz saffar,4
1. Department of Genetics, Faculty of Sciences, Shahrekord University, Shahrekord, Iran 2. Toxicology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 3. Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran 4. Department of Genetics, Faculty of Sciences, Shahrekord University, Shahrekord, Iran
Introduction: Scorpion venom is a valuable source containing various potent biomolecules. Over the years, the unique physiological properties and biochemical characteristics of scorpion peptides have been discovered by researchers. They represent novel potent compounds for development of novel drugs. More studies illustrate the pharmacological effect of venom components and their importance in treatment of diseases, including cancer, cardiovascular, microbial, autoimmune diseases and etc. Furthermore, Scorpion venom contains A2 phospholipases, serine proteases, metalloproteases, lipolysis-activating peptides (LVPs) and hyaluronidases, proteins and peptides (antimicrobial and toxic peptides that affect ion channels). Mesobuthus eupeus, a member of Buthidae family, is the most frequent scorpion species in Iran. This species is responsible for approximately 45% of scorpion sting cases in Iran. Small ion channel blocker peptides in scorpion venom cause various physiological effects in humans and insects, for instance: changes in the excitability of the central and peripheral nervous system, changes in the activity of smooth and skeletal muscles, and disruption of membrane stability by affecting ion channels. Therefor, identifying scorpion venom components uncovers important macromolecules responsible for scorpion sting symptoms or promising components for drug design or bioinsecticides.
Methods: After analyzing the transcriptome obtained using RNA extraction and subsequent cDNA library synthesis of the venom gland of Mesobuthus eupeus, blast analysis of obtained peptides was done. We found a novel beta-toxin affecting sodium channels, which represents unique potentials.
Analyzing the structure and physiochemical characteristics of the recognized peptide was done using Bioinformatic websites and software. Finally, three-dimensional structure of this peptide was determined by homology modeling.
Results: The newly recognized peptide consists of 73 amino acids containing eight cysteine residues forming four disulfide bridges, reveals a good solubility in water, theorical pI of 7.89 and molecular weight of 8336.53 g/mol. It was submitted to GenBank under the name meuNa8.
meuNa8, shares a high similarity with a beta-insect excitatory toxin LqhIT1b from Leiurus quinquestriatus hebraeus. It is a potent anti-insect peptide.
Conclusion: meuNa8 is a potent small toxin-derived molecule, highly similar to the LqhIT1b, indicates the potential of affecting on the sodium channels of insects.
Investigating the function of this protein in the future and identifying physiological processes will provide a lucrative hotbed for designing and production of safe biological insecticides.