Amplification and Molecular Identification of cDNA sequence coding for a peptide toxin from the venomous gland of the Khuzestan province scorpion Mesobuthus eupeus

The Mesobuthus eupeus scorpion venoms are known to contain α-toxin peptides, many of which interfere with K ion channel function. These toxin peptides have important value in the pharmacology and physiology studies of specific K channel of cells.
Given the lack of information of the molecular biology of peptides in the toxin of Iranian scorpions, the aim of this study is Amplification and Analyses of cDNA sequence coding for a peptide toxin from the venomous gland of the Khuzestan province scorpion Mesobuthus eupeus.
Total RNA was extracted from the venom glands of scorpion Mesobuthus eupeus collected from Khuzestan province of Iran and then cDNA was synthesized with the modified oligo (dT) primer. By applying the Semi-nested RT-PCR using homologous primers, the fragments of 227 bp were amplified and sequenced.
The full-length sequence of coding region was 174 bp which contained an open reading frame of 57 amino acids with a predicted molecular mass of 6.434 KDa and theoretical pI of 5.12. It contains a signal peptide of 19, propeptide of 4 and a mature peptide of 34 amino acids. For comparison of this peptide with the similar sequences registered in NCBI database, BLAST program was used. This protein with homology to the “Scorpion toxin-like domain” belongs to the Toxin-6 super family.
Multiple alignment of the putative amino acid sequence of this gene exhibited the highest sequence identity with lesser Asian scorpion M. eupeus venom potassium channel α-toxin-1. This high sequence similarity indicates that this gene is a member of α-toxin from the Iranian Mesobuthus eupeus.