The integration of proteins with DNA nanotechnology would enable materials with diverse applications in biology, medicine, and engineering. Here, we describe a method for the incorporation of bioactive fibronectin domain proteins with DNA nanostructures using two orthogonal coiled-coil peptides. One peptide from each coiledcoil pair is attached to a DNA origami cuboid in a multivalent fashion by attaching the peptides to DNA handles. These structures can then be assembled into one-dimensional arrays through the addition of a fibronectin domain linker genetically fused with the complementary peptides to those on the origami. We validate array formation using two different self-assembly protocols and characterize the fibers by atomic force and electron microscopy. Finally, we demonstrate that surfaces coated with the protein−DNA nanofibers can serve as biomaterial substrates for fibroblast adhesion and spreading with the nanofibers showing enhanced bioactivity compared to that of the monomeric protein.

Integrating proteins with DNA nanotechnology would enable materials with diverse applications in biology, medicine, and engineering. Here, we describe a method for incorporating bioactive fibronectin domain proteins with DNA nanostructures using two orthogonal coiled-coil peptides. One peptide from each coiled-coil pair is attached to a DNA origami cuboid in a multivalent fashion by attaching the peptides to DNA handles. These structures can then be assembled into one-dimensional arrays through the addition of a fibronectin domain linker genetically fused with the complementary peptides to those on the origami. We validate array formation using two different self-assembly protocols and characterize the fibers by atomic force and electron microscopy. Finally, we demonstrate that surfaces coated with the protein-DNA nanofibers can serve as biomaterial substrates for fibroblast adhesion and spreading, with the nanofibers enhancing bioactivity compared with the monomeric protein.

: The use of biological molecules with programmable self-assembly properties is an attractive route to functional nanomaterials. Proteins and peptides have been used extensively for these systems due to their biological relevance and large number of supramolecular motifs, but it is still difficult to build highly anisotropic and programmable nanostructures due to their high complexity. Oligonucleotides, by contrast, have the advantage of programmability and reliable assembly, but lack biological and chemical diversity. In this review, we discuss systems that merge protein or peptide self-assembly with the addressability of DNA. We outline the various self-assembly motifs used, the chemistry for linking polypeptides with DNA, and the resulting nanostructures that can be formed by the interplay of these two molecules. Finally, we close by suggesting some interesting future directions in hybrid polypeptide-DNA nanomaterials, and potential applications for these exciting hybrids.

In cells, membrane fusion is mediated by SNARE proteins, whose activities are calcium-dependent. While several non-native membrane fusion mechanisms have been demonstrated, few can respond to external stimuli. Here, we develop a calcium-triggered DNA-mediated membrane fusion strategy where fusion is regulated using surface-bound PEG chains that are cleavable by the calcium-activated protease calpain-1.

The extracellular matrix is a highly dynamic environment, and the precise temporal presentation of biochemical signals is critical for regulating cell behavior during development, healing, and disease progression. To mimic this behavior, we developed a modular DNA-based hydrogel platform to enable independent and reversible control over the immobilization of multiple biomolecules during in vitro cell culture. We combined reversible DNA handles with a norbornene-modified hyaluronic acid hydrogel to orthogonally add and remove multiple biomolecule-DNA conjugates at user-defined timepoints. We demonstrated that the persistent presentation of the cell adhesion peptide RGD was required to maintain cell spreading on hyaluronic acid hydrogels. Further, we discovered the delayed presentation of osteogenic growth peptide (OGP) increased alkaline phosphatase activity compared to other temporal variations. This finding is critically important when considering the design of OGP delivery approaches for bone repair. More broadly, this platform provides a unique approach to tease apart the temporal role of multiple biomolecules during development, regeneration, and disease progression.