Center for Functional Nanomaterials Seminar

Fascination with nucleic acids has transcended their role as the carrier of genetic information. Nucleic acids are being pursued as promising therapeutic agents, versatile bioengineering materials, and model biophysical systems. Our research is inspired by the prevalence of compact DNA/RNA assemblies in biology and bioengineering.
Observing DNA as one of the most highly charged biomolecules, we aimed to elucidate the role of ubiquitous cations in the self-assembly of liquid crystalline DNA. Towards this goal, we have combined small angle x-ray scattering methods and physical theories to quantify how the interaction between DNA helices is modulated by cations of various valences. Surprisingly, the electrostatic repulsion between DNA is reversed into attraction by tri- and tetra-valent cations, and the reversal was found to be abrupt (all or none). Small cations thus act as switches to manipulate DNA assemblies. Our recent work probes the liquid crystalline genomic DNA inside bacteriophage lambda, and provided the missing experimental quantification of the rather large DNA pressure (~50 atmospheres) inside the phage. In addition to my long-standing interest in synchrotron-based instrumentations, my future research focuses on the bioengineering aspects of DNA-cation complexes, such as DNA-templated growth of functional nanocrystals and the development of conductive M-DNA helices.