Identifying Plasmodium falciparum merozoite surface antigen 3 (MSP3) protein peptides that bind specifically to erythrocytes and inhibit merozoite invasion.
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 erythrocytes became saturable, had nanomolar affinity constants, and became sensitive on being treated with neuraminidase and trypsin but were resistant to chymotrypsin treatment. All of them specifically recognized 45-, 55-, and 72-kDa erythrocyte membrane proteins. They all presented alpha-helix structural elements. All HABPs inhibited in vitro P. falciparum merozoite invasion of erythrocytes by ~55%-85%, suggesting that MSP-3 protein's role in the invasion process probably functions by using mechanisms similar to those described for other MSP family antigens.
Fundación Instituto de Immunologia de Colombia, and Universidad Nacional de Columbia. luis_rodriguez@fidic.org.co
Luis E
LE
Rodríguez
Hernando
H
Curtidor
Marisol
M
Ocampo
Javier
J
Garcia
Alvaro
A
Puentes
John
J
Valbuena
Ricardo
R
Vera
Ramses
R
López
Manuel E
ME
Patarroyo
D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry* / Q000502:physiology; D001665:Binding Sites; D002918:Chymotrypsin / Q000494:pharmacology; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism* / Q000469:parasitology; D006801:Humans; D016778:Malaria, Falciparum / Q000378:metabolism / Q000469:parasitology / Q000517:prevention & control*; D009439:Neuraminidase / Q000494:pharmacology; D010446:Peptide Fragments / Q000378:metabolism*; D010963:Plasmodium falciparum / Q000378:metabolism / Q000469:parasitology*; D011485:Protein Binding; D015800:Protozoan Proteins / Q000737:chemistry* / Q000502:physiology; D013379:Substrate Specificity; D014357:Trypsin / Q000494:pharmacology
D000953:Antigens, Protozoan; D003432:Cross-Linking Reagents; D010446:Peptide Fragments; D015800:Protozoan Proteins; C089133:merozoite surface protein 3, Plasmodium; D009439:Neuraminidase; D002918:Chymotrypsin; D014357:Trypsin