Rlb. Milek et al., Assembly and expression of a synthetic gene encoding the antigen Pfs48/45 of the human malaria parasite Plasmodium falciparum in yeast, VACCINE, 18(14), 2000, pp. 1402-1411
Pfs48/45 is an important transmission-blocking vaccine candidate antigen of
the human malaria parasite Plasmodium falciparum. This study was aimed at
synthesis of recombinant Pfs48/45 containing conformation-constrained epito
pes of the native antigen in yeast. Since in the yeast Saccharomyces cerevi
siae induction of gene-expression led to prematurely terminated transcripts
, an entirely synthetic gene of higher GC content was assembled. Replacemen
t of the AT rich natural gene by the synthetic gene relieved the observed p
remature transcription termination. Nevertheless, recombinant protein expre
ssion could not be detected. In contrast, in the yeast Pichia pastoris low
levels of recombinant Pfs48/45 were produced upon induction of synthetic ge
ne expression. The recombinant protein was shown to be disulphide-bridge co
nstrained, but was not recognised by transmission-blocking antibodies and d
id not induce transmission-blocking sera in mice. (C) 2000 Elsevier Science
Ltd. All rights reserved.