Enhancing DNA Crystal Durability through Chemical Crosslinking.
Three-dimensional (3D) DNA crystals have been envisioned as a powerful tool for the positional control of biological and non-biological arrays on the nanoscale. However, most DNA crystals contain short duplex regions that can result in low thermal stability. Additionally, because DNA is a polyanion, DNA crystals often require high cation concentrations to maintain their integrity. Here, we demonstrate that a DNA alkylating mustard, bis(2-chloroethyl)amine, can form interstrand crosslinks within a model 3D DNA crystal. The crosslinking procedure did not alter crystal X-ray diffraction properties, but it did significantly improve the overall stability of the crystals under a variety of conditions. Crosslinked crystals showed enhanced stability at elevated temperature and were stable at Mg(2+) concentrations as low as 1 mm. Remarkably, the crosslinked crystals showed significant resistance to DNase I treatment, while also having improved longevity in tissue culture mediums. Characterization of the crosslinked species suggest that there are multiple crosslinking sites, but that the most prevalent interstrand crosslink involves an unpaired 3'-terminal guanosine residue. The improved stability of these DNA crystals suggests that simple treatment with alkylating reagents might be sufficient to stabilize crystals and other DNA constructs for improved functionality in biological and non-biological applications.
Department of Chemistry & Biochemistry, University of Maryland, 8314 Paint Branch Drive, College Park, 20742, MD, USA.
Diana
D
Zhang
Department of Chemistry & Biochemistry, University of Maryland, 8314 Paint Branch Drive, College Park, 20742, MD, USA. paukstel@umd.edu.|Maryland NanoCenter, University of Maryland, College Park, 20742, MD, USA. paukstel@umd.edu.
Paul J
PJ
Paukstelis
D003432:Cross-Linking Reagents / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D003850:Deoxyribonuclease I / Q000378:metabolism; D009690:Nucleic Acid Conformation; D014961:X-Ray Diffraction
D003432:Cross-Linking Reagents; D004247:DNA; D003850:Deoxyribonuclease I
DNA crosslinking; DNA crystals; nanotechnology; thermal stability