Human serum albumin (HSA), the most abundant serum protein in healthy humans, plays important roles in many physiological processes and has wide clinical and research applications. Despite several efforts to obtain recombinant HSA (rHSA) from bacterial and eukaryotic expression systems, a low-cost and high-yield method for rHSA production is not available. The large molecular weight and high disulphide content hamper the expression and production of rHSA using bacterial hosts. Hence, a strategy that uses a fusion technique and engineered Escherichia coli strains was employed to improve the expression of soluble rHSA in the bacterial cytoplasm. The solubilities of the b'a' domain of human protein disulphide isomerase (PDIb'a')- and maltose-binding protein (MBP)-tagged rHSA expressed in Origami 2 at 18 °C were notably increased by up to 90.1% and 96%, respectively. A simple and efficient protocol for rHSA purification was established and approximately 9.46 mg rHSA was successfully obtained from a 500-mL culture at 97% purity. However, rHSA was mostly obtained in soluble oligomeric form. By introducing a simple refolding and size-exclusion chromatography step, monomeric rHSA was obtained at 34% yield. Native polyacrylamide gel electrophoresis confirmed the similarity in the molecular weights between E. coli-derived monomeric rHSA and commercial monomeric HSA.

中文翻译：

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使用麦芽糖结合蛋白和蛋白质二硫键异构酶对可溶性重组人血清白蛋白进行细菌过表达和纯化。

人血清白蛋白（HSA）是健康人体内最丰富的血清蛋白，在许多生理过程中起着重要作用，并具有广泛的临床和研究应用。尽管为从细菌和真核表达系统获得重组HSA（rHSA）进行了数项努力，但还没有一种低成本，高产量的rHSA生产方法。高分子量和高二硫化物含量阻碍了使用细菌宿主的rHSA的表达和生产。因此，采用了融合技术和工程化大肠杆菌菌株的策略，以改善细菌细胞质中可溶性rHSA的表达。人蛋白质二硫键异构酶（PDIb'a' ）和麦芽糖结合蛋白（MBP）标记的rHSA在Origami 2中在18°C时表达分别显着增加了分别高达90.1％和96％。建立了简单有效的rHSA纯化方案，并从纯度为97％的500 mL培养物中成功获得了约9.46 mg rHSA。但是，rHSA主要以可溶性寡聚形式获得。通过引入简单的重折叠和尺寸排阻色谱步骤，可以以34％的收率获得单体rHSA。天然聚丙烯酰胺凝胶电泳证实，大肠杆菌衍生的单体rHSA与商业单体HSA的分子量相似。rHSA主要以可溶性寡聚形式获得。通过引入简单的重折叠和尺寸排阻色谱步骤，以34％的收率获得了单体rHSA。天然聚丙烯酰胺凝胶电泳证实，大肠杆菌衍生的单体rHSA与商业单体HSA的分子量相似。rHSA主要以可溶性寡聚形式获得。通过引入简单的重折叠和尺寸排阻色谱步骤，以34％的收率获得了单体rHSA。天然聚丙烯酰胺凝胶电泳证实，大肠杆菌衍生的单体rHSA与商业单体HSA的分子量相似。