Kaslow D C, Hui G, Kumar S
Molecular Vaccine Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
Mol Biochem Parasitol. 1994 Feb;63(2):283-9. doi: 10.1016/0166-6851(94)90064-7.
Four antigenic variants of the 19-kDa carboxy terminal fragment of Plasmodium falciparum merozoite surface protein, MSP1 (MSP1(19)), were expressed in Saccharomyces cerevisiae as a histidine-tagged, secreted polypeptides (rMSP1(19)s). Structural analysis of the rMSP1(19)s indicated that a single amino acid change (E to Q) in the first EGF-like domain of the yeast-secreted rMSP1(19) proteins caused a significant change in their disulfide bond-dependent conformation. The antigenicity of the rMSP1(19)s were qualitatively and quantitatively analyzed by direct and competitive binding ELISAs. The data indicate that conserved and variant B cell determinants of MSP1(19), as well as epitopes that are known targets of protective antibodies, were recreated authentically in the rMSP1(19)s. Secretion of histidine-tagged rMSP1(19)s using the expression system described may be an efficient and effective means of producing a properly folded immunogen for a human vaccine against the blood stages of P. falciparum.
恶性疟原虫裂殖子表面蛋白1（MSP1）的19-kDa羧基末端片段的四种抗原变体（MSP1(19)），在酿酒酵母中作为带组氨酸标签的分泌型多肽（rMSP1(19)s）表达。对rMSP1(19)s的结构分析表明，酵母分泌的rMSP1(19)蛋白的第一个表皮生长因子（EGF）样结构域中的单个氨基酸变化（E变为Q）导致其依赖二硫键的构象发生显著变化。通过直接和竞争结合酶联免疫吸附测定（ELISA）对rMSP1(19)s的抗原性进行了定性和定量分析。数据表明，MSP1(19)的保守和可变B细胞决定簇以及已知为保护性抗体靶点的表位在rMSP1(19)s中真实再现。使用所述表达系统分泌带组氨酸标签的rMSP1(19)s可能是生产用于预防恶性疟原虫血液阶段的人用疫苗的正确折叠免疫原的一种高效且有效的方法。
