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目的寻找恶性疟原虫裂殖子表面主要蛋白Ｐ１９５中的红细胞结合位点，为设计疫苗阻断裂殖子入侵红细胞提供实验依据。方法在大肠杆菌中分８段表达Ｐ１９５蛋白。各段蛋白用镍亲和层析柱分离，然后复性。将得到的各段蛋白免疫家兔，制备抗血清。在体外培养疟原虫至成熟裂殖体期，将各段蛋白及其相应的抗血清分别加入到培养基上清中，继续培养２４小时，检查红细胞感染率。通过感染率了解各段蛋白及其抗体对裂殖子入侵红细胞的影响。结果Ｐ１９５蛋白中氨基酸序列为３８３～５９５（Ｍ６），５９５～８９７（Ｍ７），１３９７～１６６３（Ｍ１１）的三段蛋白的抗血清具有抑制裂殖子入侵红细胞的作用，而其中Ｍ６蛋白片段也具有抑制裂殖子入侵红细胞的作用。结论Ｐ１９５蛋白中氨基酸序列为３８３～５９５的一段序列，Ｍ６可能含恶性疟原虫识别人红细胞的位点，该位点可以作为疟疾疫苗的候选抗原。
Objective To find the erythrocyte binding site of the major protein P195 on the surface of merozoite of Plasmodium falciparum, and to provide an experimental basis for designing a vaccine to block the invasion of erythrocytes by merozoites. Methods P195 protein was expressed in 8 segments in E. coli. Each protein was separated by nickel affinity chromatography and then refolded. Rabbits were immunized with the obtained fragments to prepare antisera. In vitro culture of malaria parasite to mature schizont stage, each segment of the protein and its corresponding antiserum were added to the medium supernatant, cultured for 24 hours, check the rate of infection of red blood cells. Infection rate through the understanding of each segment of the protein and its antibodies on the impact of merozoite invasion of red blood cells. Results The antiserum against the three proteins of P195 with the amino acid sequence of 383-595 (M6), 595-897 (M7) and 1397-1663 (M11) inhibited the invasion of erythrocytes, and the M6 protein fragment With the inhibition of merozoites invasion of red blood cells. Conclusion The amino acid sequence of P195 protein is a fragment of 383-595. M6 may contain the site of human erythrocytes that recognizes Plasmodium falciparum, which may serve as a candidate antigen for malaria vaccine.