Receptor-binding studies of the DBLγ domain of Plasmodium falciparum erythrocyte membrane protein 1 from a placental isolate
| Autor: | Gwladys Bertin, Grazyna Faure, Philippe Deloron, Mo-Quen Klinkert, Graham A. Bentley, Nicaise Tuikue Ndam, Alain Chaffotte, Cyril Badaut, Ayman Khattab |
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| Rok vydání: | 2007 |
| Předmět: |
Chemical Phenomena
medicine.drug_class Placenta Amino Acid Motifs Molecular Sequence Data Plasmodium falciparum Protozoan Proteins Sodium Chloride Monoclonal antibody Protein Structure Secondary law.invention chemistry.chemical_compound law Native state medicine Animals Humans Trypsin Amino Acid Sequence Chondroitin sulfate Receptor Molecular Biology Conserved Sequence Sequence Homology Amino Acid biology Chemistry Physical Circular Dichroism Surface Plasmon Resonance biology.organism_classification Molecular biology Kinetics Chondroitin Sulfate Proteoglycans chemistry Biochemistry Chondroitin sulfate proteoglycan biology.protein Recombinant DNA Parasitology Antibody Sequence Alignment Protein Binding |
| Zdroj: | Molecular and Biochemical Parasitology. 151:89-99 |
| ISSN: | 0166-6851 |
| Popis: | We have previously identified a number of DBLgamma domains in Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) transcripts obtained from placental parasite isolates, showing that they bind specifically to chondroitin sulfate A (CSA) (Khattab A, Kun J, Deloron P, Kremsner PG, Klinkert MQ. Variants of Plasmodium falciparum erythrocyte membrane protein 1 expressed by different placental parasites are closely related and adhere to chondroitin sulfate A. J Infect Dis 2001;183:1165-9). Here we give a more detailed physico-chemical and binding characterisation of the soluble, recombinant DBLgamma domain derived from one of these isolates. Results from circular dichroism and limited proteolysis experiments are consistent with the recombinant domain being expressed with the native fold. Specific binding of DBLgamma to placental cryosections was demonstrated by labeling with antibodies raised against the recombinant domain; binding was diminished after treatment of the cryosections with chondroitinase or by blocking with anti-CSA antibody, showing that CSA mediates the interaction. Binding of the DBLgamma domain to purified placental chondroitin sulfate proteoglycan (CSPG) was also studied using surface plasmon resonance techniques, with DBLgamma as analyte and CSPG immobilised on the sensor chip; these quantitative measurements gave an affinity constant in the mu-molar range under the conditions used. The native conformation of the DBLgamma domain is essential for CSPG recognition since binding to the sensor chip is abolished when the protein is irreversibly reduced. As with the placental cryosections, association was significantly reduced after treating the immobilised CSPG with chondroitinase. Together, these results demonstrate specific interaction between the DBLgamma domain and the placental receptor. |
| Databáze: | OpenAIRE |
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