title: The malaria circumsporozoite protein: interaction of the conserved regions I and II-plus with heparin-like oligosaccharides in heparan sulfate.
abstract: The malaria circumsporozoite (CS) protein binds to glycosaminoglycans from heparan sulfate proteoglycans on the cell surface of hepatocytes and is specifically cleared from the bloodstream by the liver. We show here that the two conserved regions, I and II-plus, of the CS protein, in a concerted action, preferentially bind to highly sulfated heparin-like oligosaccharides in heparan sulfate. In a concentration-dependent manner, peptides representing region I and region II-plus inhibited the binding of recombinant CS protein to HepG2 cells by 62 and 84%, respectively. Furthermore, the action of endoproteinase Arg-C, which cleaves the recombinant CS constructs CS27IVC and CSFZ(Cys) predominantly at the conserved region I, was inhibited by heparin in a concentration-dependent fashion. CSFZ(Cys), which has a higher affinity to HSPGs than CS27IVC, was stabilized by heparin at a w/w ratio (CS protein:glycosaminoglycan) of 20/1, whereas full protection of CS27IVC required more heparin (5/1). Heparan sulfate provided full protection of CSFZ(Cys) only at a ratio of 1/10. Native fucoidan as well as normally sulfated fuco-oligosaccharides (0.76 mol sulfate/mol fucose) inhibited Plasmodium berghei development in HepG2 cells by 84 and 66%, respectively, in a concentration-dependent manner and sporozoite invasion into CHO cells by 80%. Desulfated fucoidan oligosaccharides were inactive. These results may explain the selective interaction between the CS protein and the unique heparan sulfate from liver, which is noted for its unusually high degree of sulfation, and may provide a plausible explanation for the selective targeting of the malaria CS protein to the liver.
authors.affiliation: Department of Medical and Molecular Parasitology, NYU Medical Center, New York, New York 10010, USA.
authors.forename: P
authors.initials: P
authors.lastname: Ying
authors.forename: M
authors.initials: M
authors.lastname: Shakibaei
authors.forename: M S
authors.initials: MS
authors.lastname: Patankar
authors.forename: P
authors.initials: P
authors.lastname: Clavijo
authors.forename: R C
authors.initials: RC
authors.lastname: Beavis
authors.forename: G F
authors.initials: GF
authors.lastname: Clark
authors.forename: U
authors.initials: U
authors.lastname: Frevert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D017124:Conserved Sequence; D006224:Cricetinae; D019812:Heparan Sulfate Proteoglycans; D006493:Heparin / Q000378:metabolism; D019763:Heparin Lyase; D006497:Heparan Sulfate / Q000737:chemistry / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D013058:Mass Spectrometry; D008863:Microspheres; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D010962:Plasmodium berghei / Q000187:drug effects / Q000502:physiology; D010963:Plasmodium falciparum; D011133:Polysaccharide-Lyases / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism / Q000494:pharmacology; D011509:Proteoglycans / Q000378:metabolism; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D019812:Heparan Sulfate Proteoglycans; D006493:Heparin; D019763:Heparin Lyase; D006497:Heparan Sulfate; D009844:Oligosaccharides; D011133:Polysaccharide-Lyases; D011134:Polysaccharides; D011509:Proteoglycans; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; C041595:circumsporozoite protein, Protozoan; C007789:fucoidan; C044499:submandibular proteinase A; C021349:heparitinsulfate lyase