DNA-Templated Self-Assembly of Protein Arrays and Highly Conductive Nanowires

“…4a the resistivity was estimated to be 4 × 10 −5 Ωm which is considerably higher than that expected for polycrystalline silver 33 but on par with previous reports of biomolecule templated Ag nanowires. 8,33,34 To ensure that conductivity is from the nanowires and not random silver precipitates that accidentally bridged the electrodes, control measurements were taken on both a broken device (Fig. 4b) and between unconnected electrodes in the immediate vicinity of the device.…”

Section: Electronic Properties Of Metallic Collagen Nanowiresmentioning

confidence: 99%

Self-assembled collagen-like peptide fibers as templates for metallic nanowires

et al. 2008

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Inspired by nature's ability to fabricate supramolecular nanostructures from the bottom-up, materials scientist have become increasingly interested in the use of biomolecules like DNA, peptides, or proteins as templates for the creation of novel nanostructures and nanomaterials. Although the advantages of self-assembling biomolecular structures clearly lie in their chemical diversity, spatial control, and numerous geometric architectures, it is challenging to elaborate them into functional hybrid inorganic-bionanomaterials without rendering the biomolecular scaffold damaged or dysfunctional. In this study, attachment of gold nanoparticles to collagen-related self-assembling peptides at L-lysine residues incorportated within the peptides sequence and the N-terminus led to metal nanoparticle-decorated fibers. After electroless silver plating, these fibers were completely metalized, creating electrically conductive nanowires under mild conditions while leaving the peptide fiber core intact. This study demonstrates the bottom-up assembly of synthetic peptidic fibers under mild conditions and their potential as templates for other complex inorganic-organic hybrid nanostructures.

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“…Toward this end, we investigated the dependence of enzymatic activity on the number of surrounding NAD + -modified swinging arms attached to a DNA-scaffolded 4×4 tile (Fig. 3c) 26 . For the G6pDH-NAD + structure, the activity increased almost linearly as the number of NAD + -modified arms increased from 1 to 4, indicating that G6pDH activity remains well below saturation.…”

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confidence: 99%

Multi-enzyme complexes on DNA scaffolds capable of substrate channelling with an artificial swinging arm

et al. 2014

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The general design of the swinging arm nanostructure complex is shown in Fig. 1a, where a two-enzyme cascade consisting of glucose-6 phosphate dehydrogenase (G6pDH) 19 and malic dehydrogenase (MDH) 20 is displayed on a DNA double-crossover (DX) tile scaffold 21 (DNA sequences for all structures used in this study are shown in Supplementary Figs. S1-S7).G6pDH catalyzes the oxidation of glucose-6-phosphate and the reduction of NAD + to NADH.Subsequently, MDH catalyzes the reduction of oxaloacetate to malic acid using the NADH produced by G6pDH. To facilitate channeling of NADH between G6pDH and MDH, an NAD + -3 functionalized poly(T) 20 oligonucleotide was attached to the DNA tile surface halfway between G6pDH and MDH (see Supplementary Figs. S8-S21 for a detailed description of conjugation, assembly and purification of the nanostructured complex). Fig. 1b shows a native polyacrylamide gel electrophoresis (PAGE) analysis of the assembled enzyme complex, together with various sub-complexes. Both the gel results and the chromatogram resulting from sizeexclusion chromatography ( Supplementary Fig. S21) demonstrate assembly of the G6pDH-NAD + -MDH swinging arm cascade with >80% yield. The assembled mixture was further purified by size exclusion chromatography for enzyme activity assays. Assembly of the complete complex was also visualized by atomic force microscopy (AFM) ( Fig. 1c and Supplementary Fig. S57 for larger view images), where the presence of the enzymes on the structure is confirmed by differences in height ("brightness") compared to the surface of the DNA tile.To first explore the parameters and understand the kinetics and mechanism of the restricted diffusion mediated by the ssDNA swinging arm, we developed a simplified model system ( Supplementary Fig. S22). In this model, a Cy3 reporter dye takes the place of NAD + on the single-stranded poly(T) 20 arm, whereas a BHQ fluorescence quencher and a Cy5 energy transfer acceptor dye replace one or both enzymes on selected probe positions surrounding the swinging arm (Fig. 2a). An oligonucleotide sequence (5'-ATA GTG AAA) was extended from the 5' end of the poly(T) 20 sequence and positioned halfway between the quencher and acceptor, allowing the arm to transiently hybridize to the probes that each bear the complementary sequence (5'-TTT CAC TAT) in analogy to the binding of NAD + /NADH to the dehydrogenases. To characterize the distance dependence of the diffusive transport and binding mediated by the swinging arm using smFRET, we chose a design in which a single Cy5-labeled capture probe was placed at one of three topologically accessible distances from the Cy3-labeled arm: 7 nm (21 base pairs), 14 nm (42 base pairs) and 21 nm (63 base pairs). As shown in Fig. 2b, the most efficient hybridization to the capture probe was observed at 7 nm, where ~94% of all swinging arms were associated with the Cy5 probe at equilibrium (leading to high FRET). As the distance increased, the equilibrium fraction of captured swinging arms decreased to ~58% at 14 nm and only ...

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DNA-Templated Self-Assembly of Protein Arrays and Highly Conductive Nanowires

Cited by 1,688 publications

References 26 publications

Programmable disorder in random DNA tilings

Programmable disorder in random DNA tilings

Self-assembled collagen-like peptide fibers as templates for metallic nanowires

Multi-enzyme complexes on DNA scaffolds capable of substrate channelling with an artificial swinging arm

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