The complexity and variety of physiological targets with which snake venom toxins interact make them important candidates for models in the development of new drugs and biological tools. The venoms from Viperidae snakes are rich sources of proteolytic enzymes that exert various biological activities in the prey or victim, such as activation of the complement system and inflammation, changes in cell differentiation, interactions with the hemostatic system, among others. Snake venom serine proteases (SVSPs) act mainly on plasma proteins, generating a variety of physiological changes with effects on platelet aggregation, blood coagulation, fibrinolysis, blood pressure, complement system and nervous system. However, the complexity of the mechanisms by which SVSPs affect the homeostasis of the victim was not yet completely clarified. Therefore, this project aims to find new perspectives on the functionality of a SVSP from Crotalus durissus collilineatus, called collinein-1, in order to expand the fields of application of this class of toxins. In this context, we propose to investigate the action of collinein-1 in native, recombinant and mutant forms on different voltage-gated ion channels. Native collinein-1 will be purified from venom by a previously described chromatographic method and the recombinant enzyme will be expressed in Pichia pastoris in catalytically active and inactive forms (presenting a replacement of His43 by Arg43), according to previously standardized protocol. Toxins will be tested for their effect on various voltage-gated ion channels (Kv and Nav) expressed in Xenopus laevis oocytes by electrophysiology assays. The mechanisms by which collinein-1 acts on the voltage-gated ion channels will be investigated by electrophysiological assays using catalytically inactive toxin and by testing the reversibility of collinein-1 blocking effect. Ionic channels play important cellular functions such as excitation of nerves and muscle cells, regulation of blood pressure, mobility and sperm capacitation and modulation of tumor cell proliferation. Despite the importance of these channels, there are few snake toxins that was already studied for their action on ion channels, which reinforces the importance of the proposed study in the search for new ion channel modulating or blocking toxins with potential application in various areas of science and/or health.
News published in Agência FAPESP Newsletter about the scholarship: