Expression of the Plasmodium falciparum protein RH5 for subsequent aptamers selection through capillary eletrophoresis

• Grant number: 13/23255-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date until: December 01, 2013
• End date until: November 30, 2014
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Alexander Henning Ulrich
• Grantee: Giovane Carreira Improta
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Plasmodium falciparum induces modifications at the surface of infected host erythrocyte surfaces in order to survive. Among these modifications, insertion of proteins occur allowing cytoadherence or absorption of nutrients. It is believed that these integrated proteins take part in the proliferation and survival of the parasite inside the erythrocyte. Based on that, we propose the development of aptamers, oligonucleotides identified by in vitro selection (SELEX) from an oligonucleotide combinatorial library, which bind with high affinity and specificity to proteins secreted by the parasite to the erythrocyte surface. Here, we propose to use as selection target the protein PfRH5 (P. falciparum reticulocyte binding like) which is essential for growth in every strain of P. falciparum, and therefore, has been chosen as candidate for the development of the vaccine. The steps developed throughout this project are going to be the expression and purification of the recombinant protein followed by the standardization of capillary electrophoresis (CE) for the selection of aptamers and two cycles of selection in vitro and fractioning of aptamer-protein complexes. The confirmation of the affinity of the selected aptamers is used as proof of principle for the development of aptamers against proteins of P. falciparum through CE. This project is part of a collaborative network that involves Brazilian and German scientists funded by the supporting agencies FAPESP and BMBF (Germany). (AU)