title: Plasmodium falciparum EBA-140 kDa protein peptides that bind to human red blood cells.
abstract: The erythrocyte-binding antigen 140 (EBA140) sequence was chemically synthesized in 61 20-mer sequential peptides covering the entire 3D7 protein strain, each of which was tested in erythrocyte-binding assays. Peptides 26135, 26144, 26147, 26160, 26170 and 26177 presented high erythrocyte-binding activity, with affinity constants ranging from 350 to 750 nM. Critical erythrocyte-binding residues were determined by competition-binding assays with glycine analogous peptides. Cross-linking assays with SDS-PAGE from high erythrocyte membrane protein binding peptides showed that all these peptides bound specifically to 25, 52 and 75 kDa erythrocyte membrane proteins. The nature of these receptor sites was studied in peptide-binding assays using enzyme-treated erythrocytes, showing that these protein receptors are susceptible to structural changes provoked by enzyme treatment (neuraminidase, trypsin or chymotrypsin). Inhibition invasion assays in 'in vitro' cultures showed that all specific high binding sequences were able to inhibit invasion by 11-69% at 200 microM concentration.
authors.affiliation: Fundación Instituto de Inmunología de Colombia and Universidad Nacional de Colombia, Cra 50 # 26-00, Bogotá, Colombia.
authors.forename: L E
authors.initials: LE
authors.lastname: Rodriguez
authors.forename: M
authors.initials: M
authors.lastname: Ocampo
authors.forename: R
authors.initials: R
authors.lastname: Vera
authors.forename: A
authors.initials: A
authors.lastname: Puentes
authors.forename: R
authors.initials: R
authors.lastname: Lopez
authors.forename: J
authors.initials: J
authors.lastname: Garcia
authors.forename: H
authors.initials: H
authors.lastname: Curtidor
authors.forename: J
authors.initials: J
authors.lastname: Valbuena
authors.forename: J
authors.initials: J
authors.lastname: Suarez
authors.forename: J
authors.initials: J
authors.lastname: Rosas
authors.forename: Z
authors.initials: Z
authors.lastname: Rivera
authors.forename: M
authors.initials: M
authors.lastname: Urquiza
authors.forename: M E
authors.initials: ME
authors.lastname: Patarroyo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology / Q000378:metabolism; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D001681:Biological Assay / Q000379:methods; D002352:Carrier Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D002918:Chymotrypsin / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry; D004912:Erythrocytes / Q000378:metabolism* / Q000469:parasitology; D006801:Humans; D007700:Kinetics; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000378:metabolism; D010963:Plasmodium falciparum / Q000276:immunology / Q000378:metabolism*; D015800:Protozoan Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D011869:Radioligand Assay; D014357:Trypsin / Q000378:metabolism
chemical_list: D000953:Antigens, Protozoan; D002352:Carrier Proteins; D003432:Cross-Linking Reagents; C438380:EBA140 protein, Plasmodium falciparum; D008565:Membrane Proteins; D015800:Protozoan Proteins; D009439:Neuraminidase; D002918:Chymotrypsin; D014357:Trypsin