Peptidomic characterization and bioactivity screening of Leiurus abdullahbayrami (scorpiones: buthidae) venom /

Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Turkey

Approval Date: 2015

Thesis Language: English

Student: Efe Erdeş



Animal venoms consist of variety of bioactive molecules, small phenolic compounds to high molecular weight polypeptides, and they exhibit almost limitless biological functions. Scorpion venoms are complex cocktails of toxins from diverse structural origin; they are particularly enriched in bioactive peptides. These peptides gained excellent affinity for their targets through millions of years of evolutionary process. Therefore, scorpion venoms may be defined as naturally selected peptide libraries and this resource offers great promise for development of novel drugs. Leiurus abdullahbayrami, a recently described scorpion species of Turkey, produces one of the most potent venoms among venomous animals that may cause severe symptoms in envenomed victims. The remarkable strength of its venom suggests the presence of highly potent peptide toxins. The aim of this work was to characterize L. abdullahbayrami venom, mainly vi focusing on the peptide content and to screen its bioactivity. For this reason biochemical and peptidomic approaches were followed as well as cellular assays to screen bioactivity. The protein content of the venom was found 54%. The comparative electrophoretic profiling with three distinct techniques highlights the high abundance of peptide neurotoxins and indeed low amounts of high molecular weight proteins in the venom. Microfluidic capillary electrophoresis not only provided superior resolution but also had the advantage of less sample requirement over other methods. 45 unique peptide masses between 1-7 kDa were detected, supporting the presence of both short-chain and long-chain neurotoxins as well as non-disulfide bridged peptides as expected. A significant proliferative effect of crude venom was seen on MCF-7 cells. The antimicrobial potential of the venom was screened on bacterial and fungal strains, and a promising activity was detected on gram negative bacteria. The venomic components responsible for the observed activities of the present study may be determined, individually, by further investigations. The bioactive molecules might be used as scaffolds for the development of novel drugs, through advanced characterization and molecular engineering endeavors. The results of this study were published in article: Erdeş et al.: Characterization of Leiurus abdullahbayrami (Scorpiones: Buthidae) venom: peptide profile, cytotoxicity and antimicrobial activity. Journal of Venomous Animals and Toxins including Tropical Diseases 2014 20:48. (doi:10.1186/1678-9199-20-48)