Vrancken Jeroen P M, Aupič Jana, Addy Christine, Jerala Roman, Tame Jeremy R H, Voet Arnout R D
Laboratory of Biomolecular Modelling and Design, Department of Chemistry, KU Leuven, Celestijnenlaan 200G, 3001 Leuven, Belgium.
Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
J Struct Biol X. 2020 May 28;4:100027. doi: 10.1016/j.yjsbx.2020.100027. eCollection 2020.
Recently an artificial protein named Pizza6 was reported, which possesses six identical tandem repeats and adopts a monomeric -propeller fold with sixfold structural symmetry. Pizza2, a truncated form that consists of a double tandem repeat, self-assembles into a trimer reconstructing the same propeller architecture as Pizza6. The ability of pizza proteins to self-assemble to form complete propellers makes them interesting building blocks to engineer larger symmetrical protein complexes such as symmetric nanoparticles. Here we have explored the self-assembly of Pizza2 fused to homo-oligomerizing peptides. In total, we engineered five different fusion proteins, of which three appeared to assemble successfully into larger complexes. Further characterization of these proteins showed one monodisperse designer protein with a structure close to the intended design. This protein was further fused to eGFP to investigate functionalization of the nanoparticle. The fusion protein was stable and could be expressed in high yield, showing that Pizza-based nanoparticles may be further decorated with functional domains.
最近报道了一种名为Pizza6的人工蛋白质，它具有六个相同的串联重复序列，并采用具有六重结构对称性的单体β-螺旋桨折叠。Pizza2是一种由双串联重复序列组成的截短形式，它能自组装成三聚体，重构出与Pizza6相同的螺旋桨结构。pizza蛋白质自组装形成完整螺旋桨的能力，使其成为构建更大对称蛋白质复合物（如对称纳米颗粒）的有趣构建模块。在这里，我们探索了与同聚化肽融合的Pizza2的自组装。我们总共设计了五种不同的融合蛋白，其中三种似乎成功组装成了更大的复合物。对这些蛋白质的进一步表征显示，有一种单分散的设计蛋白，其结构接近预期设计。这种蛋白质进一步与增强型绿色荧光蛋白（eGFP）融合，以研究纳米颗粒的功能化。该融合蛋白稳定且能高产表达，表明基于Pizza的纳米颗粒可能会进一步用功能域进行修饰。
