Challenges and Opportunities of Nontraditional Approaches to Treating Bacterial Infections.

Due to increasing rates of antimicrobial-resistant infections and the current inadequacy of the antibiotic pipeline, there is increasing interest in nontraditional approaches to antibacterial therapies. We define "traditional" agents as small-molecule agents that directly target bacterial components to exert a bacteriostatic or bactericidal effect, and "nontraditional approaches" as antimicrobial therapeutics that work through other means (ie, not a small molecule and/or utilizes a nontraditional target). Due to their atypical features, such therapies may be less susceptible to the emergence of resistance than traditional antibiotics.

Translation of DNA into a library of 13,000 synthetic small-molecule macrocycles suitable for in vitro selection.

DNA-templated organic synthesis enables the translation, selection, and amplification of DNA sequences encoding synthetic small-molecule libraries. Previously we described the DNA-templated multistep synthesis and model in vitro selection of a pilot library of 65 macrocycles. In this work, we report several key developments that enable the DNA-templated synthesis of much larger (>10,000-membered) small-molecule libraries.

Effects of template sequence and secondary structure on DNA-templated reactivity.

DNA-templated organic synthesis enables the translation, selection, and amplification of DNA sequences encoding synthetic small-molecule libraries. As the size of DNA-templated libraries increases, the possibility of forming intramolecularly base-paired structures within templates that impede templated reactions increases as well. To achieve uniform reactivity across many template sequences and to computationally predict and remove any problematic sequences from DNA-templated libraries, we have systematically examined the effects of template sequence and secondary structure on DNA-templated reactivity.

DNA-templated organic synthesis and selection of a library of macrocycles.

The translation of nucleic acid libraries into corresponding synthetic compounds would enable selection and amplification principles to be applied to man-made molecules. We used multistep DNA-templated organic synthesis to translate libraries of DNA sequences, each containing three "codons," into libraries of sequence-programmed synthetic small-molecule macrocycles. The resulting DNA-macrocycle conjugates were subjected to in vitro selections for protein affinity.

Translation of DNA into synthetic N-acyloxazolidines.

The translation of DNA into synthetic molecules enables their manipulation by powerful evolution-based methods previously available only to proteins and nucleic acids. The development of increasingly sophisticated DNA-templated small-molecule syntheses is crucial to broadening the scope of this approach. Here, we report the translation of DNA templates into monocyclic and bicyclic N-acyloxazolidines using multistep DNA-templated organic synthesis.