John Jairo Valbuena

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The process of Mycobacterium tuberculosis infection of the macrophage implies a very little-known initial recognition and adherence step, important for mycobacterial survival; many proteins even remain like hypothetical. The Rv1510c gene, encoding a putatively conserved membrane protein, was investigated by analysing the M. tuberculosis genome sequence data(More)
Binding assays were carried out with 20 amino acid long peptides covering the complete 200-kDa Liver stage antigen (LSA) 3 protein sequence to identify its HepG2 cell binding regions. Seventeen HepG2 cell high-activity binding peptides (HABPs) were identified in the LSA-3 protein. Seven HABPs were found in the nonrepeat (NRA) region A; five of these formed(More)
Receptor-ligand interactions between synthetic peptides and normal human erythrocytes were studied to determine Plasmodium falciparum merozoite surface protein-3 (MSP-3) FC27 strain regions that specifically bind to membrane surface receptors on human erythrocytes. Three MSP-3 protein high activity binding peptides (HABPs) were identified; their binding to(More)
Adhesion of mature asexual stage Plasmodium falciparum parasite-infected erythrocytes (iRBC) to the vascular endothelium is a critical event in the pathology of Plasmodium falciparum malaria. It has been suggested that the clag gene family is essential in cytoadherence to endothelial receptors. Primers used in PCR and RT-PCR assays allowed us to determine(More)
Plasmodium falciparum apical membrane antigen 1 (AMA-1) is expressed during both the sporozoite and merozoite stage of the parasite's life cycle. The role placed by AMA-1 during sporozoite invasion of hepatocytes has not been made sufficiently clear to date. Identifying the sequences involved in binding to hepatocytes is an important step towards(More)
The gene encoding the Mycobacterium tuberculosis Rv2536 protein is present in the Mycobacterium tuberculosis complex (as assayed by PCR) and transcribed (as determined by RT-PCR) in M. tuberculosis H37Rv, M. tuberculosis H37Ra, M. bovis BCG, and M. africanum strains. Rabbits immunized with synthetic polymer peptides from this protein produced antibodies(More)
MAEBL is an erythrocyte binding protein located in the rhoptries and on the surface of mature merozoites, being expressed at the beginning of schizogony. The structure of MAEBL originally isolated from rodent malaria parasites suggested a molecule likely to be involved in invasion. We thus became interested in identifying possible MAEBL functional regions.(More)
Tryptophan-threonine-rich antigen (TryThrA) is a Plasmodium falciparum homologue of Plasmodium yoelii-infected erythrocyte membrane pypAg-1 antigen. pypAg-1 binds to the surface of uninfected mouse erythrocytes and has been used successfully in vaccine studies. The two antigens are characterized by an unusual tryptophan-rich domain, suggesting similar(More)
Synthetic 20-mer long non-overlapped peptides, from STEVOR protein, were tested in RBC binding assays for identifying STEVOR protein regions having high RBC binding activity and evaluating whether these regions inhibit Plasmodium falciparum in vitro invasion. Affinity constants, binding site number per cell and Hill coefficients were determined by(More)
Receptor-ligand interactions between synthetic peptides and normal human erythrocytes were studied to determine P. falciparum merozoite surface protein-10 (MSP-10) regions specifically binding to membrane surface receptors on human erythrocytes. Three MSP-10 protein High Activity Binding Peptides (HABPs) were identified, whose binding to erythrocytes became(More)