Two-Helix Supramolecular Proteomimetic Binders Assembled via PNA-Assisted Disulfide Crosslinking

Glyco-DNA: Enzymatic Synthesis of Base-Modified and Hypermodified DNA Displaying up to Four Different Monosaccharide Units in the Major Groove

A portfolio of six modified 2'-deoxyribonucleoside triphosphate (dNTP) derivatives derived from 5-substituted pyrimidine or 7-substituted 7-deazapurine bearing different carbohydrate units (d-glucose, d-galactose, d-mannose, l-fucose, sialic acid and N-Ac-d-galactosamine) tethered through propargyl-glycoside linker was designed and synthesized via the Sonogashira reactions of halogenated dNTPs with the corresponding propargyl-glycosides. The nucleotides were found to be good substrates for DNA polymerases in enzymatic primer extension and PCR synthesis of modified and hypermodified DNA displaying up to four different sugars. Proof of concept binding study of sugar-modified oligonucleotides with concanavalin A showed positive effect of avidity and sugar units count.

Templating Peptide Chemistry with Nucleic Acids: Toward Artificial Ribosomes, Cell-Specific Therapeutics, and Novel Protein-Mimetic Architectures

In biology, nanomachines like the ribosome use nucleic acid templates to synthesize polymers in a sequence-specific, programmable fashion. Researchers have long been interested in using the programmable properties of nucleic acids to enhance chemical reactions via colocalization of reagents using complementary nucleic acid handles. In this review, we describe progress in using nucleic acid templates, handles, or splints to enhance the covalent coupling of peptides to other peptides or oligonucleotides. We discuss work in several areas: creating ribosome-mimetic systems, synthesizing bioactive peptides on DNA or RNA templates, linking peptides into longer molecules and bioactive antibody mimics, and scaffolding peptides to build protein-mimetic architectures. We close by highlighting the challenges that must be overcome in nucleic acid-templated peptide chemistry in two areas: making full-length, functional proteins from synthetic peptides and creating novel protein-mimetic architectures not possible through macromolecular folding alone.

DNA-Mediated Peptide Assembly into Protein Mimics

The design of new protein structures is challenging due to their vast sequence space and the complexity of protein folding. Here, we report a new modular DNA-templated strategy to construct protein mimics. We achieve the spatial control of multiple peptide units by conjugation with DNA and hybridization to a branched DNA trimer template followed by covalent stapling of the preorganized peptides into a single unit. A library of protein mimics with different lengths, sequences, and heptad registers has been efficiently constructed. DNA-templated protein mimics show an α-helix or coiled-coil motif formation even when they are constructed from weakly interacting peptide units. Their attached DNA handles can be used to exert dynamic control over the protein mimics' secondary and tertiary structures. This modular strategy will facilitate the development of DNA-encoded protein libraries for the rapid discovery of new therapeutics, enzymes, and antibody mimics.