Structural and functional studies with key-proteins for local mionecrosis establishment by bothropic envenomation

Abstract

Envenoming caused by snakebites is considered a public health problem in many tropical and subtropical countries and has recently been included in the list of Neglected Tropical Diseases by the World Health Organization. Accidents caused by snakes from Bothrops genus deserves special attention in Latin America because more than 70% of the ophidic accidents reported in this area are caused by snakes of the mentioned genus. One of the main complications regarding bothropic envenomation is the proeminent local muscle damage caused by the bite of these snakes, deserving special attention the activity played by two classes of proteins. One of them consists of phospholipases A2 (PLA2s) that act directly in the muscle membrane damaging them. The other group is constituted of metalloproteases (MPs) that are known by their ability to interfere with different components of the basal membrane, consequently leading to hemorrage. In this work we porpose structural and functional studies with both of these classes of proteins because the lesion caused by them cannot be prevented or reverted by serum therapy administration. We are going to perform X-ray structural studies with these two classes of toxins complexed to inhibitors alredy known in the literature aiming a better comprehension of the structural bases of the mechanisms underlying their inhibition. Additionally, we are going to perform site-directed-mutagenesis studies aiming to confirm the residues responsible for the myotoxicity expression in Lys49-PLA2s, docking studies with class-I and class-III metalloproteases aiming the identification of the possible binding site for two new inhibitors recently characterized as presenting anti-hemorragic activity, and virtual screening studies tryning to identify possible new ligands that may become potencial inhibitors for two groups of myotoxic PLA2s found in the bothropic venom.