Fabrication of 3D high-order protein assemblies by applying multivalent interactions

Abstract

In nature, proteins are major building blocks and many protein-based assemblies are used in various cell processes. Therefore, developing artificial protein assemblies have been studied based on these natural processes. In this study, new 3D high-order protein assemblies are introduced through multivalent interactions between proteins. For protein-protein interactions, binding pairs were connected to backbone proteins, and oligomeric proteins were used to make multivalent interactions with multiple binding sites. First, I developed double-layered protein nano-prisms that is discrete by linking binding pairs, SpyCatcher/SpyTag, to previously designed GFP oligomers. The GFP nano-prisms can also have flexible structures through the addition of longer linker between GFP oligomer and binding pair. This strategy is applied to other oligomeric proteins to produce not only prism structures but also 1D fibrous structures. In addition, protein mega-cages were fabricated by combining two oligomers outside the metal-mediated protein condensates. The protein mega-cages are stable enough to carry some biomolecules such as DNA and proteins inside. Furthermore, it is expected that these constructed protein assemblies can be used as new biomaterials.