Human growth hormone (hGH) plays an important role in growth control, growth promotion, cell development, and regulation of numerous metabolic pathways in the human body and has been approved by the U.S. FDA for the treatment of several human dysfunctions. Over-expression of recombinant hGH (rhGH) affords a misfolded form in cytoplasm of Escherichia coli, and the refolding step required to obtain active rhGH greatly affects its production costs. Herein, the cleavable self-aggregating tag (cSAT) scheme was used for the expression and purification of rhGH in E. coli. Four aggregating tags (L₆KD/α3-peptide/EFK8/ELK16) successfully drove rhGH into active protein aggregates. After the Mxe GyrA intein-mediated cleavage, 2.8–21.4 μg rhGH/mg wet cell weight was obtained at laboratory scale, of which the L₆KD fusion achieved the highest rhGH yield. The further refined rhGH maintained 92% of the bioactivity compared to commercial rhGH. The self-assembling of the aggregating tag might physically separate the hGH polypeptide chains, which in turn was beneficial to its folding into the active form. This study provided a simple and cost-effective approach for active rhGH production, and suggested an opportunity for improve folding of recombinant proteins in E. coli.

人类生长激素 (hGH) 在人体内的生长控制、生长促进、细胞发育和多种代谢途径的调节中起着重要作用，并已被美国 FDA 批准用于治疗多种人类功能障碍。重组 hGH (rhGH) 的过度表达在大肠杆菌的细胞质中提供了错误折叠的形式，并且获得活性 rhGH 所需的重折叠步骤极大地影响了其生产成本。在本文中，可切割的自聚集标签 (cSAT) 方案用于在大肠杆菌中表达和纯化 rhGH 。四个聚合标签（L ₆ KD/α3-肽/EFK8/ELK16）成功地将 rhGH 驱动到活性蛋白质聚集体中。在Mxe 之后在实验室规模获得 GyrA 内含肽介导的裂解，2.8-21.4 μg rhGH/mg 湿细胞重量，其中 L ₆ KD 融合实现了最高的 rhGH 产量。与商业 rhGH 相比，进一步精制的 rhGH 保持了 92% 的生物活性。聚集标签的自组装可能会物理分离 hGH 多肽链，这反过来有利于其折叠成活性形式。该研究为活性 rhGH 生产提供了一种简单且具有成本效益的方法，并为改善大肠杆菌中重组蛋白的折叠提供了机会。