"Induction strategies of the recombinant 503 antigen of Leishmania i. chagasi expressed in M15 Escherichia coli"
503 antigen, recombinant Escherichia coli, Leishmaniosis, induction.
With nearly 900,000 to 1.3 million new cases annually, Leishmaniosis is a complex of diseases that can be fatal if not given proper attention. Despite its relevance in the public health system, there is no vaccine capable of preventing disease in humans so far, and its treatment is expensive and aggressive to human health. The present study aims to optimize the induction parameters of the 503 Leishmania i. chagasi antigen expressed in recombinant Escherichia coli. Hence, lactose (0.1, 1.0 e 10.0 g/L) and isopropyl-β-D-thiogalactopyranoside (IPTG) (20.0; 100.0; 500.0 e 1000.0 mM) were used and analysed as inducer molecules at different cell densities (OD600 to 0.5 and 1.0) in order to assess the influence of the induction time on the yield of the protein of interest. The results presented that the IPTG concentration of 100 μM favoured the higher antigen levels (0.087 g/L), being a lower concentration than is usually used in this type of system reported in the literature, and for lactose was 1 g/L (0.016 g/L). Thus, induction with 100.0 mM of IPTG allowed achieving the 503 antigen with a concentration 5.6 times higher than the maximum obtained when lactose was used as an inductor.