Biofabrication of functional protein nanoparticles through simple His-tag engineering

Abstract

We have developed a simple, robust and fully transversal approach for the a-la-carte fabrication of functional multimeric nanoparticles with potential biomedical applications, validated here by a set of diverse and unrelated polypeptides. The proposed concept is based on the controlled coordination between Zn2+ ions and His residues in His-tagged proteins. This approach results in the spontaneous and reproducible protein assembling as nanoscale oligomers that keep the original functionalities of the protein building blocks. The assembling of these materials is not linked to particular polypeptide features and it is based on an environment-friendly and sustainable approach. The resulting nanoparticles, with dimensions ranging between 10 and 15 nm, are regular in size, architecturally stable, fully functional, and serve as intermediates in a more complex assembling process resulting in the formation of microscale protein materials. Since most of the recombinant proteins produced by biochemical and biotechnological industries and intended for biomedical research are His-tagged, the green biofabrication procedure proposed here can be straightforward applied to a huge spectrum of protein species for their conversion into their respective nanostructured formats.