Data for Efficient overexpression and purification of SARS-CoV-2 Nucleocapsid proteins in Escherichia coli

The datasets provided relate to identification of minor contaminants found in recombinant native and 6-his-tagged SARS-CoV-2 Nucelocapsid proteins. 
Abstract of publication: The fundamental biology of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (Ncap), its use in diagnostic assays and its potential application as a vaccine component have received considerable attention since the outbreak of the Covid19 pandemic in late 2019. Here we report the scalable expression and purification of soluble, immunologically active, SARS-CoV-2 Ncap in <em>Escherichia coli</em>. Codon-optimised synthetic genes encoding the original Ncap sequence and four common variants with an N-terminal 6His affinity tag (sequence MHHHHHHG) were cloned into an inducible expression vector carrying a regulated bacteriophage T5 synthetic promoter controlled by <em>lac</em> operator binding sites. The constructs were used to express Ncap proteins and protocols developed which allow efficient production of purified Ncap with yields of over 200 mg per litre of culture media. These proteins were deployed in ELISA assays to allow comparison of their responses to human sera. Our results suggest that there was no detectable difference between the 6His-tagged and untagged original Ncap proteins but there may be a slight loss of sensitivity of sera to other Ncap isolates.

本数据集所涉内容为重组天然型及带6组氨酸标签（6-his-tagged）的严重急性呼吸综合征冠状病毒2（SARS-CoV-2）核衣壳蛋白（Nucleocapsid protein，Ncap）中微量污染物的鉴定工作。
相关研究论文摘要如下：2019年末新冠（COVID-19）疫情暴发以来，严重急性呼吸综合征冠状病毒2（SARS-CoV-2）核衣壳蛋白的基础生物学特性、其在诊断检测中的应用及作为疫苗组分的潜在价值均受到广泛关注。本研究报道了在大肠杆菌（Escherichia coli）中可规模化表达与纯化可溶性、具有免疫活性的SARS-CoV-2核衣壳蛋白的方法。研究人员将编码原始核衣壳蛋白序列及四种常见变体的密码子优化合成基因，与带有N端6组氨酸亲和标签（序列为MHHHHHHG）的片段克隆至携带由乳糖操纵子（lac operator）结合位点调控的噬菌体T5合成启动子的诱导型表达载体中。利用上述重组构建体实现核衣壳蛋白的表达，并开发出高效纯化工艺，每升培养基可获得产量超200 mg的纯化核衣壳蛋白。将所得蛋白应用于酶联免疫吸附试验（ELISA），以对比其与人类血清的结合反应。研究结果显示，带6组氨酸标签的原始核衣壳蛋白与无标签原始核衣壳蛋白之间未检测到显著差异，但人类血清对其他核衣壳分离株的检测灵敏度或存在轻微损失。