Plasmodium falciparum: Cloned and Expressed CIDR Domains of PfEMP1 Bind to Chondroitin Sulfate A

• Published in: Experimental parasitology 2000-06, Vol.95 (2), p.113-121
• Main Authors: Degen, Roland, Weiss, Niklaus, Beck, Hans-Peter
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Binding, Competitive; Biological and medical sciences; Cell Adhesion; CHO Cells; CHO, Chinese hamster ovary; Chondroitin ABC Lyase - metabolism; chondroitin sulfate A; Chondroitin Sulfates - metabolism; CIDR, cysteine-rich interdomain region; Cloning, Molecular; Cricetinae; CRM, cysteine-rich motif; CSA, chondroitin sulfate A; CSase ABC, chondroitinase ABC (EC 4.2.2.4.); cytoadherence; DBL1 domain, Duffy binding like domain 1; Dose-Response Relationship, Drug; erythrocyte membrane protein 1; FACS, fluorescence-activated cell scan; FITC, fluorescein isothiocyanate; Flow Cytometry; Fundamental and applied biological sciences. Psychology; His, histidine; ICAM1, intercellular adhesion molecule 1; iRBC, infected red blood cell; Life cycle. Host-agent relationship. Pathogenesis; Molecular Sequence Data; PECAM1, platelet/endothelial cell adhesion molecule 1; PfEMP1 protein; PfEMP1, Plasmodium falciparum erythrocyte membrane protein 1; Plasmodium falciparum; Plasmodium falciparum - chemistry; Plasmodium falciparum - genetics; Plasmodium falciparum - metabolism; Protein Binding; Protozoa; Protozoan Proteins - chemistry; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Sequence Alignment; Transfection; VCAM1, vascular cell adhesion molecule 1
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1006/expr.2000.4512

Degen, R., Weiss, N., and Beck, H.-P. 2000. Plasmodium falciparum: Cloned and expressed CIDR domains of PfEMP1 bind to chondroitin sulfate A. Experimental Parasitology95, 113–121. Adherence of erythrocytes infected with mature asexual Plasmodium falciparum parasites (iRBC) to microvascular endothelial cells contributes to the pathology of P. falciparum malaria. It has been shown that the variant P. falciparum erythrocyte membrane protein 1 (PfEMP1) confers adhesion to a wide range of cell surface receptors. Previously, the cysteine-rich interdomain region (CIDR) of PfEMP1 has been identified as binding site to CD36. We provide evidence that the same region can also mediate binding to chondroitin sulfate A (CSA). CIDR domains of two different parasite strains were expressed in Escherichia coli as a 6xHis-tagged protein. Purified recombinant protein bound to Chinese hamster ovary (CHO) cells which naturally express chondroitin sulfate A. Treatment of wild-type CHO cells with chondroitinase ABC reduced binding up to 94.4%. Competitive binding using soluble CSA inhibited binding to CHO cells by up to 100% at 2 mg/ml and by 62.4% at 0.5 mg/ml, whereas 1 mg/ml heparan sulfate had only a little effect (18.1%). In contrast, a recombinant 6xHis-tagged DBL1 domain showed no binding to wild-type CHO cells. Such an approach of analyzing various domains of PfEMP1 as recombinant proteins may elucidate their functions and may lead to novel anti-adherence therapeutics, especially for maternal malaria infections.