Spatially Resolved Peptide-DNA Nanoassemblages for Biomarker Detection: A Synergy of DNA-Directed Immobilization and Nanografting.

Peptide microarrays are becoming a promising alternative to protein microarrays due to the challenges associated with protein immobilization and purification. Here, we put forward a novel experimental-based approach that combines DNA-directed immobilization, nanografting, and atomic force height measurements to immobilize computationally designed cyclic peptide on an ultra-flat gold substrate. This procedure yields peptide-DNA nanoarrays, which can bind to the solvent-exposed site on the Beta-2-microglobulin (β2m).

Binary control of enzymatic cleavage of DNA origami by structural antideterminants.

Controlling DNA nanostructure interaction with protein is essential in developing nanodevices with programmable function, reactivity, and stability for biological and medical applications. Here, we show that the sequence-specific action of restriction endonucleases towards sharp triangular or rectangular DNA origami exhibits a novel, binary 'on/off' behaviour, as canonical recognition sites are either essentially fully reactive, or strongly resistant to enzymatic cutting. Moreover, introduction of structural defects in the sharp triangle can activate an otherwise unreactive site, with a site-to-defect distance of ∼50 nm.

Computational design of cyclic peptides for the customized oriented immobilization of globular proteins.

The oriented immobilization of proteins, key for the development of novel responsive biomaterials, relies on the availability of effective probes. These are generally provided by standard approaches based on in vivo maturation and in vitro selection of antibodies and/or aptamers. These techniques can suffer technical problems when a non-immunogenic epitope needs to be targeted.

pH-Controlled Assembly of DNA Tiles.

We demonstrate a strategy to trigger and finely control the assembly of supramolecular DNA nanostructures with pH. Control is achieved via a rationally designed strand displacement circuit that responds to pH and activates a downstream DNA tile self-assembly process. We observe that the DNA structures form under neutral/basic conditions, while the self-assembly process is suppressed under acidic conditions.