Sánchez Julieta María, Carratalá José Vicente, Serna Naroa, Unzueta Ugutz, Nolan Verónica, Sánchez-Chardi Alejandro, Voltà-Durán Eric, López-Laguna Hèctor, Ferrer-Miralles Neus, Villaverde Antonio, Vazquez Esther
Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Plaça Cívica s/n, Bellaterra, 08193 Barcelona, Spain.
Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Plaça Cívica s/n, Bellaterra, 08193 Barcelona, Spain.
Pharmaceutics. 2022 Mar 10;14(3):602. doi: 10.3390/pharmaceutics14030602.
The coordination between histidine-rich peptides and divalent cations supports the formation of nano- and micro-scale protein biomaterials, including toxic and non-toxic functional amyloids, which can be adapted as drug delivery systems. Among them, inclusion bodies (IBs) formed in recombinant bacteria have shown promise as protein depots for time-sustained protein release. We have demonstrated here that the hexahistidine (H6) tag, fused to recombinant proteins, impacts both on the formation of bacterial IBs and on the conformation of the IB-forming protein, which shows a higher content of cross-beta intermolecular interactions in H6-tagged versions. Additionally, the addition of EDTA during the spontaneous disintegration of isolated IBs largely affects the protein leakage rate, again protein release being stimulated in His-tagged materials. This event depends on the number of His residues but irrespective of the location of the tag in the protein, as it occurs in either C-tagged or N-tagged proteins. The architectonic role of H6 in the formation of bacterial IBs, probably through coordination with divalent cations, offers an easy approach to manipulate protein leakage and to tailor the applicability of this material as a secretory amyloidal depot in different biomedical interfaces. In addition, the findings also offer a model to finely investigate, in a simple set-up, the mechanics of protein release from functional secretory amyloids.
富含组氨酸的肽与二价阳离子之间的协同作用支持纳米级和微米级蛋白质生物材料的形成，包括有毒和无毒的功能性淀粉样蛋白，它们可被用作药物递送系统。其中，重组细菌中形成的包涵体（IBs）已显示出有望作为蛋白质储存库实现蛋白质的持续释放。我们在此证明，与重组蛋白融合的六组氨酸（H6）标签，既影响细菌包涵体的形成，也影响形成包涵体的蛋白质的构象，在带有H6标签的变体中，该蛋白质显示出更高含量的交叉β分子间相互作用。此外，在分离的包涵体自发解体过程中添加EDTA会极大地影响蛋白质泄漏率，带有组氨酸标签的材料中的蛋白质释放再次受到刺激。这一现象取决于组氨酸残基的数量，但与标签在蛋白质中的位置无关，因为在C端标记或N端标记的蛋白质中都会发生。H6在细菌包涵体形成中的结构作用，可能是通过与二价阳离子配位，为控制蛋白质泄漏以及调整这种材料作为不同生物医学界面中的分泌性淀粉样蛋白储存库的适用性提供了一种简便方法。此外，这些发现还提供了一个模型，以便在简单的设置中精细研究功能性分泌性淀粉样蛋白释放蛋白质的机制。
