The disulfide bond structure of Plasmodium apical membrane antigen-1

Abstract

Apical membrane antigen-1 (AMA-1) of Plasmodium falciparum is one of the leading asexual blood stage antigens being considered for inclusion in a malaria vaccine. The ability of this molecule to induce a protective immune response has been shown to be dependent upon a conformation stabilized by disulfide bonds. In this study we have utilized the reversed-phase high performance liquid chromatography of dithiothreitol-reduced and nonreduced tryptic digests of Plasmodium chabaudi AMA-1 secreted from baculovirus- infected insect cells, in conjunction with N-terminal sequencing and electrospray-ionization mass spectrometry, to identify and assign disulfide- linked peptides. All 16 cysteine residu..