Abstract Cyclin D3 is a regulatory protein associated in a variety of human tumors. Despite several studies involving Cyclin D1 and D2, there are few articles that investigate the role of Cyclin D3. Therefore, this study aimed to produce and characterize Cyclin D3 using the Escherichia coli expression system and a protein refolding protocol. The anionic detergent SDS was used to solubilize the protein, then the solution were kept at 4 °C to precipitate SDS. After removing the precipitate by centrifugation, the supernatant was applied to the Ni-NTA column to purify His- tagged Cyclin D3. The recombinant protein shown to be refolded in a denaturation study by fluorescence spectroscopy at increasing concentrations of guanidine hydrochloride. The protein secondary structure, evaluated by circular dichroism, is composed of 39 % α helix and 15 % β-strands. In addition, the study aimed to validate the refolding protocol used to obtain Cyclin D3 from E. coli inclusion bodies.

中文翻译：

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人细胞周期蛋白 D3 的过度表达和重折叠。一个可靠的方法与否？

摘要 细胞周期蛋白 D3 是一种与多种人类肿瘤相关的调节蛋白。尽管有几项涉及细胞周期蛋白 D1 和 D2 的研究，但很少有文章研究细胞周期蛋白 D3 的作用。因此，本研究旨在使用大肠杆菌表达系统和蛋白质重折叠方案生产和表征细胞周期蛋白 D3。使用阴离子去污剂 SDS 溶解蛋白质，然后将溶液保持在 4°C 以沉淀 SDS。离心除去沉淀后，将上清液加入 Ni-NTA 柱以纯化带有 His 标签的细胞周期蛋白 D3。在通过荧光光谱法进行的变性研究中，重组蛋白显示在盐酸胍浓度增加时重新折叠。通过圆二色性评估的蛋白质二级结构，由 39% α 螺旋和 15% β-链组成。此外，该研究旨在验证用于从大肠杆菌包涵体中获取细胞周期蛋白 D3 的重折叠方案。