expression of leishmania major lmsti1 in yeast pichia pastoris

background: leishmania major lmsti1 is a conserved protein among different species of leishmania, and expressed in both amastigote and promastigote forms of l. major life cycle. it has previously been expressed in bacterial systems. m aterials and methods: to express lmsti1 in the methylotrophic yeast         pichia pastoris ( p. pastoris ), the shuttle vector ppicza containing gene lmsti1 was constructed under the control of the aox1 promoter. the recombinant vector was electro-transformed into p. pastoris, and induced by 0.5% methanol in the buffered medium. the expression of the lmsti1 protein was visualized in the total soluble protein of p. pastoris by 12% sds-page, and further confirmed by western blotting with l.major -infected mouse sera and hrp-conjugated goat anti-mouse igg as the first and secondary antibodies, respectively. results : the expression level was 0.2% of total soluble proteins. conclusion: it might be possible to use this formulation as a whole yeast candidate vaccine against cutaneous leishmanization.