14 research outputs found
Selective in Situ Assembly of Viral Protein onto DNA Origami
Engineering hybrid proteināDNA
assemblies in a controlled
manner has attracted particular attention, for their potential applications
in biomedicine and nanotechnology due to their intricate folding properties
and important physiological roles. Although DNA origami has served
as a powerful platform for spatially arranging functional molecules, <i>in situ</i> assembly of proteins onto DNA origami is still challenging,
especially in a precisely controlled and facile manner. Here, we demonstrate <i>in situ</i> assembly of tobacco mosaic virus (TMV) coat proteins
onto DNA origami to generate programmable assembly of hybrid DNA origamiāprotein
nanoarchitectures. The protein nanotubes of controlled length are
precisely anchored on the DNA origami at selected locations using
TMV genome-mimicking RNA strands. This study opens a new route to
the organization of protein and DNA into sophisticated proteināDNA
nanoarchitectures by harnessing the viral encapsidation mechanism
and the programmability of DNA origami
Multilayer DNA Origami Packed on Hexagonal and Hybrid Lattices
āScaffolded DNA origamiā has been proven
to be a
powerful and efficient approach to construct two-dimensional or three-dimensional
objects with great complexity. Multilayer DNA origami has been demonstrated
with helices packing along either honeycomb-lattice geometry or square-lattice
geometry. Here we report successful folding of multilayer DNA origami
with helices arranged on a close-packed hexagonal lattice. This arrangement
yields a higher density of helical packing and therefore higher resolution
of spatial addressing than has been shown previously. We also demonstrate
hybrid multilayer DNA origami with honeycomb-lattice, square-lattice,
and hexagonal-lattice packing of helices all in one design. The availability
of hexagonal close-packing of helices extends our ability to build
complex structures using DNA nanotechnology
Design Space for Complex DNA Structures
Nucleic
acids have emerged as effective materials for assembling
complex nanoscale structures. To tailor the structures to function
optimally for particular applications, a broad structural design space
is desired. Despite the many discrete and extended structures demonstrated
in the past few decades, the design space remains to be fully explored.
In particular, the complex finite-sized structures produced to date
have been typically based on a small number of structural motifs.
Here, we perform a comprehensive study of the design space for complex
DNA structures, using more than 30 distinct motifs derived from single-stranded
tiles. These motifs self-assemble to form structures with diverse
strand weaving patterns and specific geometric properties, such as
curvature and twist. We performed a systematic study to control and
characterize the curvature of the structures, and constructed a flat
structure with a corrugated strand pattern. The work here reveals
the broadness of the design space for complex DNA nanostructures
Programming Self-Assembly of DNA Origami Honeycomb Two-Dimensional Lattices and Plasmonic Metamaterials
Scaffolded
DNA origami has proven to be a versatile method for
generating functional nanostructures with prescribed sub-100 nm shapes.
Programming DNA-origami tiles to form large-scale 2D lattices that
span hundreds of nanometers to the micrometer scale could provide
an enabling platform for diverse applications ranging from metamaterials
to surface-based biophysical assays. Toward this end, here we design
a family of hexagonal DNA-origami tiles using computer-aided design
and demonstrate successful self-assembly of micrometer-scale 2D honeycomb
lattices and tubes by controlling their geometric and mechanical properties
including their interconnecting strands. Our results offer insight
into programmed self-assembly of low-defect supra-molecular DNA-origami
2D lattices and tubes. In addition, we demonstrate that these DNA-origami
hexagon tiles and honeycomb lattices are versatile platforms for assembling
optical metamaterials via programmable spatial arrangement of gold
nanoparticles (AuNPs) into cluster and superlattice geometries
DNA-Nanostructure-Guided Assembly of Proteins into Programmable Shapes
The development of
methods to synthesize artificial protein complexes
with precisely controlled configurations will enable diverse biological
and medical applications. Using DNA to link proteins provides programmability
that can be difficult to achieve with other methods. Here, we use
DNA origami as an āassemblerā to guide the linking
of proteināDNA conjugates using a series of oligonucleotide
hybridization and displacement operations. We constructed several
isomeric protein nanostructures, including a dimer, two types of trimer
structures, and three types of tetramer assemblies, on a DNA origami
platform by using a C3-symmetric building block composed of a protein
trimer modified with DNA handles. Our approach expands the scope for
the precise assembly of protein-based nanostructures and will enable
the formulation of functional protein complexes with stoichiometric
and geometric control
Design Space for Complex DNA Structures
Nucleic
acids have emerged as effective materials for assembling
complex nanoscale structures. To tailor the structures to function
optimally for particular applications, a broad structural design space
is desired. Despite the many discrete and extended structures demonstrated
in the past few decades, the design space remains to be fully explored.
In particular, the complex finite-sized structures produced to date
have been typically based on a small number of structural motifs.
Here, we perform a comprehensive study of the design space for complex
DNA structures, using more than 30 distinct motifs derived from single-stranded
tiles. These motifs self-assemble to form structures with diverse
strand weaving patterns and specific geometric properties, such as
curvature and twist. We performed a systematic study to control and
characterize the curvature of the structures, and constructed a flat
structure with a corrugated strand pattern. The work here reveals
the broadness of the design space for complex DNA nanostructures
Structurally Ordered Nanowire Formation from Co-Assembly of DNA Origami and Collagen-Mimetic Peptides
We describe the co-assembly of two
different building units: collagen-mimetic
peptides and DNA origami. Two peptides <b>CP</b><sup><b>++</b></sup> and <b>sCP</b><sup><b>++</b></sup> are designed
with a sequence comprising a central block (Pro-Hyp-Gly) and two positively
charged domains (Pro-Arg-Gly) at both N- and C-termini. Co-assembly
of peptides and DNA origami two-layer (<b>TL</b>) nanosheets
affords the formation of one-dimensional nanowires with repeating
periodicity of ā¼10 nm. Structural analyses suggest a face-to-face
stacking of DNA nanosheets with peptides aligned perpendicularly to
the sheet surfaces. We demonstrate the potential of selective peptide-DNA
association between face-to-face and edge-to-edge packing by tailoring
the size of DNA nanostructures. This study presents an attractive
strategy to create hybrid biomolecular assemblies from peptide- and
DNA-based building blocks that takes advantage of the intrinsic chemical
and physical properties of the respective components to encode structural
and, potentially, functional complexity within readily accessible
biomimetic materials
Site-Specific Surface Functionalization of Gold Nanorods Using DNA Origami Clamps
Precise control over surface functionalities
of nanomaterials offers
great opportunities for fabricating complex functional nanoarchitectures
but still remains challenging. In this work, we successfully developed
a novel strategy to modify a gold nanorod (AuNR) with specific surface
recognition sites using a DNA origami clamp. AuNRs were encapsulated
by the DNA origami through hybridization of single-stranded DNA on
the AuNRs and complementary capture strands inside the clamp. Another
set of capture strands on the outside of the clamp create the specific
recognition sites on the AuNR surface. By means of this strategy,
AuNRs were site-specifically modified with gold nanoparticles at the
top, middle, and bottom of the surface, respectively, to construct
a series of well-defined heterostructures with controlled āchemical
valenceā. Our study greatly expands the utility of DNA origami
as a tool for building complex nanoarchitectures and represents a
new approach for precise tailoring of nanomaterial surfaces
Plasmonic Toroidal Metamolecules Assembled by DNA Origami
We show hierarchical
assembly of plasmonic toroidal metamolecules
that exhibit tailored optical activity in the visible spectral range.
Each metamolecule consists of four identical origami-templated helical
building blocks. Such toroidal metamolecules show a stronger chiroptical
response than monomers and dimers of the helical building blocks.
Enantiomers of the plasmonic structures yield opposite circular dichroism
spectra. Experimental results agree well with the theoretical simulations.
We also show that given the circular symmetry of the structures s
distinct chiroptical response along their axial orientation can be
uncovered via simple spin-coating of the metamolecules on substrates.
Our work provides a new strategy to create plasmonic chiral platforms
with sophisticated nanoscale architectures for potential applications
such as chiral sensing using chemically based assembly systems
Programmable Multivalent DNA-Origami Tension Probes for Reporting Cellular Traction Forces
Mechanical
forces are central to most, if not all, biological processes,
including cell development, immune recognition, and metastasis. Because
the cellular machinery mediating mechano-sensing and force generation
is dependent on the nanoscale organization and geometry of protein
assemblies, a current need in the field is the development of force-sensing
probes that can be customized at the nanometer-length scale. In this
work, we describe a DNA origami tension sensor that maps the piconewton
(pN) forces generated by living cells. As a proof-of-concept, we engineered
a novel library of six-helix-bundle DNA-origami tension probes (DOTPs)
with a tailorable number of tension-reporting hairpins (each with
their own tunable tension response threshold) and a tunable number
of cell-receptor ligands. We used single-molecule force spectroscopy
to determine the probesā tension response thresholds and used
computational modeling to show that hairpin unfolding is semi-cooperative
and orientation-dependent. Finally, we use our DOTP library to map
the forces applied by human blood platelets during initial adhesion
and activation. We find that the total tension signal exhibited by
platelets on DOTP-functionalized surfaces increases with the number
of ligands per DOTP, likely due to increased total ligand density,
and decreases exponentially with the DOTPās force-response
threshold. This work opens the door to applications for understanding
and regulating biophysical processes involving cooperativity and multivalency