Biosynthesis of Pb44, the protective antigen of sporozoites of Plasmodium berghei.
Biosynthesis of Pb44, the protective antigen of sporozoites of Plasmodium berghei.
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DOI：
10.1084/jem.154.4.1225
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发表时间：
1981-10-01
期刊：
影响因子：
--
通讯作者：
Nussenzweig RS
中科院分区：
文献类型：
--
作者：
Yoshida N;Potocnjak P;Nussenzweig V;Nussenzweig RS
在以前的文献（2）中，我们用单克隆抗体鉴定了伯氏疟原虫子孢子表面膜的保护性抗原（Pb 44）。成熟唾液腺子孢子提取物的免疫沉淀，代谢标记的L[35S]蛋氨酸使用相同的单克隆抗体，揭示了三个特定的多肽：*Pb44，*Pb52，和 *Pb54。代谢标记的 *Pb44可能与先前通过表面标记鉴定的保护性抗原相同。两种蛋白质在变性条件下具有相同的分子量和等电点，并且它们共享表位。此外，*Pb44似乎也位于细胞膜上。脉冲追踪实验的结果表明，* Pb 52是 * Pb 44的前体。*Pb54与保护性抗原之间的关系尚不清楚。这三种多肽似乎与寄生虫的发育阶段中的仅一个严格相关。它们在血液中未被检测到，但在蚊子中肠的子孢子中发现了微量。相反，在成熟的唾液腺子孢子中，它们构成蛋白质合成的主要产物。
In a previous paper (2) we identified a protective antigen (Pb44) of the surface membrane of sporozoites of Plasmodium berghei by means of a monoclonal antibody. Immunoprecipitation of extracts of mature salivary gland sporozoites, metabolically labeled with L[35S]methionine using the same monoclonal antibody, revealed three specific polypeptides: *Pb44, *Pb52, and *Pb54. Metabolically labeled *Pb44 is probably identical to the protective antigen previously identified by surface labeling. Both proteins have the same molecular weights and isoelectric points under denaturing conditions, and they share an epitope. Moreover, *Pb44 also seems to be located on the cell membrane. The results of pulse-chase experiments strongly suggest that *Pb52 is the precursor of *Pb44. The relationship between *Pb54 and the protective antigen is unknown. The three polypeptides seem to be strictly associated with only one of the developmental stage of the parasite. They were not detected in blood forms and were found in minute amounts in sporozoites from the midgut of mosquitoes. In contrast, in mature salivary gland sporozoites they constitute main products of protein synthesis.