Abstract

When expressing streptavidin recombinant polypeptide on magnetosomes (called bacterial magnetic nanoparticles, or BMPs), the presence of endogenous bacterial biotin might be detrimental. In the study, the streptavidin monomer fragment (SA_1–116) was fused with the intein N-terminal (termed precursor SA_1–116-IN), and SA_1–116-IN was expressed in E. coli (BL21). Meanwhile, the SA_117–160 fragment was fused with the C-terminal intein, and then this chimeric polypeptide was expressed on magnetosomes by fusion with magnetosome membrance protein MamF. In the in vitro protein splicing system, the purified engineered magnetosomes (BMP-SA_117–160-IC) and the SA_1–116-IN precursor were mixed. Intein-mediated trans-splicing reaction was induced to produce the functional magnetic beads BMP-SA. Our results indicate that intein-mediated protein trans-splicing may lead to efficient synthesis of the recombinant streptavidin on the magnetosomes, showing its promising potential to produce other functional magnetic nanoparticles.

中文翻译：

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重组链霉亲和素在磁小体上的内含肽介导的蛋白质反式剪接

摘要

当在磁小体（称为细菌磁性纳米粒子或 BMP）上表达链霉亲和素重组多肽时，内源性细菌生物素的存在可能是有害的。在研究中，链霉亲和素单体片段 (SA _1-116 ) 与内含肽 N 端融合（称为前体 SA _1-116 -IN），SA _1-116 -IN 在大肠杆菌（BL21）中表达。同时，SA _117-160片段与 C 端内含肽融合，然后该嵌合多肽通过与磁小体膜蛋白 MamF 融合在磁小体上表达。在体外蛋白质剪接系统中，纯化的工程磁小体 (BMP-SA _{117-160 -IC} ) 和 SA _1-116-IN 前体混合。诱导内含肽介导的反式剪接反应产生功能性磁珠BMP-SA。我们的结果表明，内含肽介导的蛋白质反式剪接可能导致在磁小体上有效合成重组链霉亲和素，显示其生产其他功能性磁性纳米颗粒的潜力。