title: Initial characterization of Pf62, a novel protein of Plasmodium falciparum identified by immunoscreening.
abstract: In order to find new antigens from Plasmodium falciparum, a complementary DNA (cDNA) library was constructed and screened. The study of expression library of P. falciparum was performed in an attempt to identify new antigens that could have potential relevance for the falciparum-malaria diagnosis and/or protection. Between the positive clones detected (ring erythrocyte surface antigen, merozoite erythrocyte surface antigen, RHOP H3, CSP, LSA), a new gene that correspond to a new protein (Pf62) was isolated and characterized. This antigen was useful for the diagnosis of malaria in enzyme-linked immunosorbent assay tests. The cDNA corresponding to this antigen and structure of the gene were characterized. Pf62 is a single copy gene that contains one exon. The Pf62 cDNA has an open reading frame of 1,599 nucleotides that code for a putative protein of 532 amino acids with a predicted molecular mass of 62 kDa. The polypeptide contains in the central section two regions of repeats of 21 and 19 amino acids, respectively. The localization of the Pf62 protein was performed by immunoblot, indirect immunofluorescence assay and immunoelectron microscopy. Pf62 is localized in the cytoplasm of the parasite and also on the surface of the infected erythrocyte. Serologic assays by using synthetic peptides designed from different antigenic regions of the Pf62 protein resulted in acceptable data of sensitivity and specificity in symptomatic malaria patients.
authors.affiliation: Centro Nacional de Medicina Tropical, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Eva M
authors.initials: EM
authors.lastname: Moyano
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: González
authors.forename: Estrella
authors.initials: E
authors.lastname: Montero
authors.forename: Laureano
authors.initials: L
authors.lastname: Cuevas
authors.forename: Esperanza
authors.initials: E
authors.lastname: Perez-Pastrana
authors.forename: Ysmael
authors.initials: Y
authors.lastname: Santa-Maria
authors.forename: Agustín
authors.initials: A
authors.lastname: Benito
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D003593:Cytoplasm / Q000737:chemistry; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004912:Erythrocytes / Q000737:chemistry / Q000469:parasitology; D005091:Exons; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D020449:Repetitive Sequences, Amino Acid / Q000235:genetics; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D015800:Protozoan Proteins