Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.
Skip to main content

<jats:title>SUMMARY</jats:title><jats:p><jats:italic>Plasmodium falciparum-infected</jats:italic> erythrocytes (IRBC) synthesize 3 histidine-rich proteins: HRP-I or the knob-associated HRP, HRP-II and HRP-III or SHARP. In order to distinguish these proteins immunochemically we prepared monoclonal antibodies which react with HRP-I, HRP-II and HRP-III, and rabbit antisera against synthetic peptides derived from the HRP-II and HRP-III sequences. A comparative analysis of diverse <jats:italic>P. falciparum</jats:italic> parasites was made using these antibodies and immunoprecipitation or Western blotting. HRP-I <jats:italic>(M<jats:sub>r</jats:sub></jats:italic> 80000–115000) was identified in all knob-positive <jats:italic>P. falciparum</jats:italic> parasites including isolates examined directly from Gambian patients. However, this protein was of lower abundance in these isolates and in 6 knob-positive, culture-adapted parasites compared to <jats:italic>Aotus</jats:italic> monkey-adapted parasites or culture-adapted parasites studied previously. HRP-II <jats:italic>(M<jats:sub>r</jats:sub></jats:italic> 60000–105000) was identified in all <jats:italic>P. falciparum</jats:italic> parasites regardless of knob-phenotype, and was recovered from culture supernatants as a secreted water-soluble protein. Within IRBC, HRP-II was found as a complex of several closely spaced bands. Cell surface radio-iodination of IRBC from several isolates and immunoprecipitation with a rabbit antiserum against the HRP-II repeat sequence identified HRP-II as a surface-exposed protein. Like HRP-I, the abundance of HRP-II was lower in the Gambian isolates than with <jats:italic>Aotus</jats:italic> monkey-adapted parasites studied earlier. Neither HRP-I nor HRP-II were identified in a knob-positive isolate of <jats:italic>P. malariae</jats:italic> collected from a Gambian patient. Analogues of these HRP were also absent from asexual parasites of diverse primate and murine malaria species screened with this panel of antibodies. HRP-III <jats:italic>(M<jats:sub>r</jats:sub></jats:italic> 40000–55000) was distinguished by its lower apparent size and by specific reaction with rabbit antibody against its 5-mer repeat sequence. HRP-III was of lowest abundance compared with the other two HRP. These antibody reagents and distinguishing properties should prove useful in studies on the separate functions of the 3 <jats:italic>P. falciparum</jats:italic> HRP.</jats:p>

Original publication

DOI

10.1017/s0031182000057681

Type

Journal article

Journal

Parasitology

Publisher

Cambridge University Press (CUP)

Publication Date

10/1987

Volume

95

Pages

209 - 227