Hetero-Diels-Alder Cycloaddition with RAFT Polymers as Bioconjugation Platform.

We introduce the bioconjugation of polymers synthesized by RAFT polymerization, bearing no specific functional end group, by means of hetero-Diels-Alder cycloaddition through their inherent terminal thiocarbonylthio moiety with a diene-modified model protein. Quantitative conjugation occurs over the course of a few hours, at ambient temperature and neutral pH, and in the absence of any catalyst. Our technology platform affords thermoresponsive bioconjugates, whose aggregation is solely controlled by the polymer chains.

Plasmon resonance tuning using DNA origami actuation.

A strategy for an innovative, continuous and reversible LSPR tuning using DNA origami actuation to modulate the nanometric separation of two gold nanoparticles has been developed. The actuation mechanism is based on DNA hybridization, in particular three different DNA sequences were shown to induce resonance shift of up to 6 nm.

DNA from natural sources in design of functional devices.

The role of DNA as structuring or templating agent has become more significant with the development of nanobiotechnology. Although short single and double stranded DNA have extensively been used as immobilization tool, as a template for nanoparticle preparation and in design of various devices such as nanomotors and biosensors, DNA from natural sources has an advantage of being abundant, cheap and readily available. Therefore, it is not surprising that there is a huge interest in making the use of natural DNA properties for both nano- and micro-applications. In this review we attempt to give an overview of the up to date applications of natural DNA, either from viral, marine or mammalian sources, in design of functional devices. This article is meant to be a starting point and a guide to the platforms in which natural DNA is employed such as DNA origami, optoelectronic devices and organic catalysis.

A facile method for preparation of tailored scaffolds for DNA-origami.

A convenient PCR cloning strategy allows one to prepare hundreds of picomoles of circular single-stranded DNA molecules, which are suitable as scaffolds for the assembly of DNA origami structures. The method is based on a combination of site-directed mutagenesis and site- and ligation-independent cloning protocols, with simultaneous insertion of a nicking endonuclease restriction site on a double-stranded plasmid of desired length and sequence.

Light induced DNA-protein conjugation.

DNA was modified with a photo-reactive caged diene allowing for the modification of dienophile containing proteins under mild irradiation conditions to afford fully functional DNA-protein conjugates.

Clickable tyrosine binding bifunctional linkers for preparation of DNA-protein conjugates.

We have prepared bifunctional linkers containing clickable functional groups that enable preparation of protein-DNA conjugates through binding onto tyrosine residues. Mild conjugation strategy was demonstrated using two proteins, streptavidin(STV) and myoglobin (Mb) and it resulted in conjugates with preserved functionality of both the proteins and DNA strands. Furthermore, we show that protein-DNA conjugates can be successfully immobilized onto solid surface containing complementary DNA strands and the enzymatic activity of Mb-DNA conjugates is even higher than that of corresponding conjugates prepared through Lys binding.