Properties of the Plasmodium falciparum homologue of a protective vaccine candidate of Plasmodium yoelii.
We describe an unusual tryptophan-rich protein of Plasmodium falciparum that contains threonine-rich repeats. The protein is encoded by a 2.5 kb gene with a two-exon structure including a short AT-rich intron that is spliced out of the mature message. The 5' end of the gene encodes a hydrophobic region, which is assumed to be a signal peptide. The peptide sequence is characterised by a tryptophan-rich region and a block of degenerate threonine repeats. The protein is synthesised throughout the asexual life cycle and has an apparent molecular weight of approximately 94 kDa. It has a variable molecular weight in different strains of P. falciparum. Length polymorphisms can be found in the intron region and the second exon. Four single nucleotide mutations are localised in the tryptophan-rich region and two were found in the threonine-repeat block. Homology searches based on gene structure and amino acid sequence revealed a relationship with a P. yoelii antigen that has been used successfully in vaccine studies. Thus, this P. falciparum antigen should be considered an additional candidate for assessment in vaccination against the asexual blood-stages of P. falciparum.
Uhlemann
A C
AC
Department of Parasitology, Institute of Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074, Tübingen, Germany.
Oguariri
R M
RM
McColl
D J
DJ
Coppel
R L
RL
Kremsner
P G
PG
Anders
R F
RF
Kun
J F
JF
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D008288:Malaria / Q000517:prevention & control; D017780:Malaria Vaccines / Q000235:genetics* / Q000276:immunology; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000276:immunology*; D010967:Plasmodium yoelii / Q000276:immunology*; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D017780:Malaria Vaccines; D008565:Membrane Proteins; D015800:Protozoan Proteins; C117490:pypag-1 protein, Plasmodium yoelii