New Insights for Native Production of MSP119, the Disulfide-Rich C-Terminal Fragment from Plasmodium falciparum Merozoite Surface Protein 1

Abstract

Malaria represents a major public health problem and an important cause of mortality and morbidity. The malaria parasites are becoming resistant to drugs used to treat the disease and still no efficient vaccine has been developed. One promising vaccine candidate is the merozoite surface protein 1 (MSP1), which has been extensively investigated as a vaccine target. The surface protein MSP1 plays an essential role in the erythrocyte invasion process and is an accessible target for the immune system. Antibodies to the carboxy-terminal region of the protein, named MSP119, can inhibit erythrocyte invasion and parasite growth. In order to develop an effective MSP119- based vaccine against malaria, production of an antigen that is recognized by protective antibodies is mandatory. To this aim, we propose a method to produce the disulfide-rich MSP119 in its native conformation based on its in vitro oxidative refolding. The native conformation of the renatured MSP119 is carefully established by immunochemical reactivity experiments, circular dichroism and NMR. MSP119 can successfully be refolded in vitro as an isolated protein or as a fusion with the maltose binding protein. The possibility to properly fold MSP119 in vitro paves the way to new approaches for high titer production of native MSP119 using Escherichia coli as a host.

Study of Specific Region of Plasmodium falciparum Nicotinamide/Nicotinate Mononucleotide Adenylyl Transferase (PfNMNAT): Characterizing a Possible Therapeutic Target

“…In previous studies, PfNMNAT has been cloned into the pET100/d-TOPO vector (Thermo Scientific), but during its expression, large amounts of insoluble aggregates known as "inclusion bodies" (IBs) are produced. For this reason, PfNMNAT was cloned into the pMal-c5x vector, which adds an MBP tag that does not interfere with the folding of the protein of interest and allows the production of active protein [13]. To date, the mechanism by which the fusion protein can modify the solubility of the protein of interest is still unclear; however, MBP is one of the most studied.…”

Validação de teste ELISA para pesquisa de anticorpos anti-MSP119 de Plasmodium vivax visando à aplicação em serviços hemoterápicos do Brasil em áreas não endêmicas para malária

“…al., 1999;Morais et. al., 2005;Akpogheneta et al, 2008) e desempenham um importante papel na imunidade à doença (Rosa et al, 2006;Bargieri et al, 2008;Lazarou et al, 2009), sendo a única região da MSP1 capaz de ter efeito de reforço nas reinfecções (Nogueira et al, 2006) e uma das subunidades mais estudadas como candidata à vacina (Hirunpetcharat et al, 1997;Planson et al, 2013). Altos níveis de IgG1 anti-MSP1 19 foram preditores de risco reduzido de sintomas e altas parasitemias por P.…”