De novo design of a genetically encoded simple viral-like coat protein for artificial viruses

Viruses are naturally evolved non-living entities and key to understand the emergence of biological complexity and life. Viruses have been implemented for gene therapy and construction of nanomaterials due to their remarkable properties such as nano-scale organization, precise self-assembly and efficient nucleic acid delivery into cells. However, their engineering and application have been severely limited by complex and not fully understood structure-function relations, safety risks, immunogenicity, intricate production, etc.

In order to overcome these limitations, we have designed a polypeptide that mimics fundamental properties of viral capsid proteins [1, 2]. The polypeptide consists of three independent blocks made up of simple amino acid sequences that provide colloidal stability, self-assembly and DNA binding. The viral-mimetic polypeptide self-assembles around a DNA template into precise and monodisperse rod-like nanostructures, similarly to the Tobacco Mosaic virus. Furthermore, the artificial rod-like viruses have high stability in physiological conditions and against enzymatic attack, and deliver pDNA and mRNA into cells with high efficiency and low toxicity. The viral-like coat polypeptide is produced monodisperse and secrete with high yield into the medium using a genetically modified P. pastoris yeast strain. Its genetically encoded multi-block design allows to program additional functionalities such as targeted delivery, self-replication and others.

References

[1] Coating of Single DNA Molecules by Genetically Engineered Protein Diblock Copolymers. Armando Hernandez-Garcia, et. al., Small 8, 3491–3501 (2012)

[2] Design and self-assembly of simple coat proteins for artificial viruses. Armando Hernandez-Garcia, et. al., Nature Nanotechnology 9, 698–702 (2014)