Expression and Purification of Recombinant Malarial Antigen Plasmodium falciparum Lactate Dehydrogenase (PfLDH) in E.Coli Expression System for Diagnostic Application

Malaria is still a fatal endemic disease caused by plasmodium parasites, most commonly transmitted by human bites transmitted by female Anopheles mosquitoes. It remains one of the biggest global threats to human health, especially in subtropical areas. The main stage of the parasite (Plasmodium falciparum) is responsible for most of those severe and lethal cases of malaria. The stage of the parasite's life cycle when it infects and replicates the phase occurring inside the host organism’s red blood cells, is typically a human, called the erythrocytic stage. Plasmodium falciparum Lactate Dehydrogenase (PfLDH) is a glycolytic enzyme that catalyses the conversion of pyruvate and lactate into energy for the body's metabolism. It is used in antimalarial medications and diagnostic tests for finding malaria because the presence of PfLDH in blood samples suggests the presence of the parasite. The focus of this study is to make recombinant PfLDH protein in Escherichia coli BL21(DE3) strain. The PfLDH gene was introduced into the expression vector pET27b(+)to construct recombinant plasmid, which was then transformed into E. Coli BL21(DE3). Next, recombinant DNA containing host cell was induced by IPTG at different concentrations, time intervals and temperature that can be grown in LB broth containing marker gene. Recombinant protein PfLDH was purified by IMAC, was analysed and was confirmed by SDS-PAGE and Western blot. It can be utilized as a biomarker for malarial Rapid Diagnostic Tests (RDTs).