Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy.
Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403, USA.
Biomolecules. 2021 Apr 27;11(5):645. doi: 10.3390/biom11050645.
Bile acids (BAs) are hydroxylated steroids derived from cholesterol that act at the intestinal level to facilitate the absorption of several nutrients and also play a role as signaling molecules. In the liver of various vertebrates, the trafficking of BAs is mediated by bile acid-binding proteins (L-BABPs). The ability to host hydrophobic or amphipathic molecules makes BABPs suitable for the distribution of a variety of physiological and exogenous substances. Thus, BABPs have been proposed as drug carriers, and more recently, they have also been employed to develop innovative nanotechnology and biotechnology systems. Here, we report an efficient protocol for the production, purification, and crystallization of chicken liver BABP (cL-BABP). By means of target expression as His-tag cL-BABP, we obtained a large amount of pure and homogeneous proteins through a simple purification procedure relying on affinity chromatography. The recombinant cL-BABP showed a raised propensity to crystallize, allowing us to obtain its structure at high resolution and, in turn, assess the structural conservation of the recombinant cL-BABP with respect to the liver-extracted protein. The results support the use of recombinant cL-BABP for the development of drug carriers, nanotechnologies, and innovative synthetic photoswitch systems.
胆汁酸（BAs）是由胆固醇衍生而来的羟基甾类化合物，在肠道水平发挥作用，促进多种营养物质的吸收，同时也作为信号分子发挥作用。在各种脊椎动物的肝脏中，胆汁酸的转运由胆汁酸结合蛋白（L-BABP）介导。BABP 具有结合疏水性或两亲性分子的能力，适合分配各种生理和外源性物质。因此，BABP 已被提议作为药物载体，最近，它们也被用于开发创新的纳米技术和生物技术系统。在这里，我们报告了一种生产、纯化和结晶鸡肝 BABP（cL-BABP）的有效方案。通过目标表达作为 His 标签 cL-BABP，我们通过依赖亲和层析的简单纯化程序获得了大量纯的和均一的蛋白质。重组 cL-BABP 表现出提高的结晶倾向，使我们能够获得其高分辨率的结构，并反过来评估重组 cL-BABP 相对于提取自肝脏的蛋白质的结构保守性。结果支持使用重组 cL-BABP 开发药物载体、纳米技术和创新的合成光开关系统。
