Igarashi M, Matsuura E, Igarashi Y, Nagae H, Matsuura Y, Ichikawa K, Yasuda T, Voelker D R, Koike T
Microbiology Laboratory, Yamasa Corporation, Choshi, Japan.
Clin Exp Immunol. 1993 Jul;93(1):19-25. doi: 10.1111/j.1365-2249.1993.tb06491.x.
A full-length cDNA coding a human beta 2-glycoprotein I (beta 2-GPI) was introduced into the baculovirus genome to construct a recombinant baculovirus. Spodoptera frugiperda (Sf9) cells were infected with the recombinant baculovirus. A protein (mol. wt 43,000) reactive with anti-beta 2-GPI antisera was produced in the insect cells and secreted into the culture medium. The recombinant beta 2-GPI was purified from the culture supernatant by sequential cardiolipin (CL)-affinity column chromatography and gel filtration. The N-terminal amino acid sequence of the protein was identical to that of the native beta 2-GPI purified from human sera, and a putative signal peptide was cleaved from the secreted form of the recombinant protein. The purified recombinant protein had a cofactor activity which enhances CL binding of anticardiolipin antibodies (aCL) in systemic lupus erythematosus (SLE) patients, as well as the native beta 2-GPI. Thus, the beta 2-GPI expressed in insect cells is an immunologically active cofactor.
将编码人β2-糖蛋白I（β2-GPI）的全长cDNA导入杆状病毒基因组，构建重组杆状病毒。用重组杆状病毒感染草地贪夜蛾（Sf9）细胞。昆虫细胞中产生了一种与抗β2-GPI抗血清反应的蛋白质（分子量43,000），并分泌到培养基中。通过连续的心磷脂（CL）亲和柱色谱和凝胶过滤从培养上清液中纯化重组β2-GPI。该蛋白质的N端氨基酸序列与从人血清中纯化的天然β2-GPI相同，并且从重组蛋白的分泌形式中切割出一个假定的信号肽。纯化的重组蛋白具有辅因子活性，可增强系统性红斑狼疮（SLE）患者中抗心磷脂抗体（aCL）与CL的结合，天然β2-GPI也是如此。因此，在昆虫细胞中表达的β2-GPI是一种具有免疫活性的辅因子。
