Molecular characterization of a novel secretory phospholipase A2 as coding gene from venom glands of Iranian Scorpio maurus (Arachnida: Scorpionidae)

Abstract Background Scorpions as a venomous arthropod can defend and capture the prey by secretion of venom into their venomic sacs. The venom is a mixture of a variety of compounds with specific biological activities, such as phospholipase A2 (PLA2) enzyme to be present in scorpion venom. This study is the first investigation of structural and molecular characterization of PLA2 from Iranian scorpion, S. maurus that can be added to the literature when targeting molecular characterization of PLA2 coding gene from venom glands of Iranian S. maurus. Results S. maurus PLA2 with 432 base pair (bp) nucleotide length encoded a protein of 144 amino acid residues and 16.34 kilodaltons (kDa). According to DiANNA 1.1 web server prediction, this protein had 5 disulfide bridges. The deposited PLA2 in GenBank (MW241004) was very similar to S. maurus (MF347455.1) with 95.14% identity. The phylogenetic analysis indicated that our PLA2 had a close relationship with insect PLA2. Our PLA2 had 38.83% identity with bee venom PLA2 according to SWISS-MODEL prediction and 100% confidence and 39% identity with insect phospholipase A2 family, which was predicted by Phyre2. Our PLA2 was similar to chain A of bee venom PLA2. Conserved domains on target PLA2 contained 17–118 amino acid in length and 45–52 amino acids in the active site. There was no signal peptide. Conclusions In the light of our results, the coding sequence of characterized PLA2 was a member of the PLA2 superfamily. According to the three-dimensional structure prediction, the target PLA2 with five disulfide bonds has a very high similarity to the structure of phospholipase A2 belonged to the group III subfamily. Interestingly, the active site residue of target PLA2 also has the His-Asp acid pair and the effective amino acid in catalytic domain of it was\({\text{H}\text{i}\text{s}}^{49}\).