title: Interaction of Plasmodium vivax Tryptophan-rich Antigen PvTRAg38 with Band 3 on Human Erythrocyte Surface Facilitates Parasite Growth.
abstract: Plasmodium tryptophan-rich proteins are involved in host-parasite interaction and thus potential drug/vaccine targets. Recently, we have described several P. vivax tryptophan-rich antigens (PvTRAgs), including merozoite expressed PvTRAg38, from this noncultivable human malaria parasite. PvTRAg38 is highly immunogenic in humans and binds to host erythrocytes, and this binding is inhibited by the patient sera. This binding is also affected if host erythrocytes were pretreated with chymotrypsin. Here, Band 3 has been identified as the chymotrypsin-sensitive erythrocyte receptor for this parasite protein. Interaction of PvTRAg38 with Band 3 has been mapped to its three different ectodomains (loops 1, 3, and 6) exposed at the surface of the erythrocyte. The binding region of PvTRAg38 to Band3 has been mapped to its sequence, KWVQWKNDKIRSWLSSEW, present at amino acid positions 197-214. The recombinant PvTRAg38 was able to inhibit the parasite growth in in vitro Plasmodium falciparum culture probably by competing with the ligand(s) of this heterologous parasite for the erythrocyte Band 3 receptor. In conclusion, the host-parasite interaction at the molecular level is much more complicated than known so far and should be considered during the development of anti-malarial therapeutics.
authors.affiliation: From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India.
authors.forename: Mohd Shoeb
authors.initials: MS
authors.lastname: Alam
authors.affiliation: From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India.
authors.forename: Vandana
authors.initials: V
authors.lastname: Choudhary
authors.affiliation: From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Zeeshan
authors.affiliation: From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India.
authors.forename: Rupesh K
authors.initials: RK
authors.lastname: Tyagi
authors.affiliation: From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Rathore
authors.affiliation: From the Department of Biotechnology, All India Institute of Medical Sciences, New Delhi-110029, India ydsharma@hotmail.com ydsharma_aiims@yahoo.com.
authors.forename: Yagya D
authors.initials: YD
authors.lastname: Sharma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D010966:Plasmodium vivax / Q000254:growth & development / Q000276:immunology*
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D000953:Antigens, Protozoan
keywords: erythrocyte; malaria; membrane protein; parasite; peptides; protein-protein interaction; receptor