A synthetic peptide whose sequence was derived from the circumsporozoite protein of Plasmodium knowlesi coupled to bovine gamma globulin has been shown to be immunogenic when administered with Freund complete adjuvant. The present experiments were designed to test the immunogenicity of the peptide when attached to a tetanus toxoid carrier and administered with alum or murabutide, both acceptabl...

Circumsporozoite protein (CSP) is the dominant protein on the surface of Plasmodium sporozoites and plays a critical role in the invasion by sporozoites of hepatocytes. Contacts between CSP and heparin sulfate proteoglycans (HSPGs) lead to the attachment of sporozoites to hepatocytes and trigger signaling events in the parasite that promote invasion of hepatocytes. The precise sequence elements...

Monoclonal antibody NYS4 recognizes a single 140 kDa antigen on the surface of Plasmodium yoelii sporozoites, an antigen which is distinct from the extensively characterized circumsporozoite (CS) protein. To more thoroughly characterize this additional surface component, a genomic expression library was screened with NYS4 and an immunoreactive clone (M4) was obtained which expressed part of the...

The circumsporozoite protein (CSP) is the major surface protein of Plasmodium sporozoites, the infective stage of malaria. Although CSP has been extensively studied as a malaria vaccine candidate, little is known about its structure. Here, we show that CSP is proteolytically cleaved by a papain family cysteine protease of parasite origin. Our data suggest that the highly conserved region I, fou...

A monoclonal antibody directed against the circumsporozoite protein on the surface of Plasmodium berghei sporozoites inhibited sporozoite motility in vitro. These immobilized sporozoites could adhere to but not invade target cultured cells. Other sporozoite-immobilizing agents also inhibited sporozoite invasion into cultured cells and did not prevent sporozoite adherence. These results indicate...

The susceptibility of Anopheles aquasalis (F3 generation) and An. darlingi (F1 generation) to Plasmodium vivax circumsporozoite protein phenotypes from a limited number of blood samples of malaria patients in Belém, state of Pará, Brazil, was examined A polymerase chain reaction was used to determine the P. vivax phenotypes in blood samples and the blood-fed infected mosquitoes were dissected a...