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Updated: Jun 10, 2026
Production of Double-stranded DNA Ministrings
Published on: February 29, 2016
Quantized folding of plasmid DNA condensed with block catiomer into characteristic rod structures promoting transgene
Kensuke Osada1, Hiroki Oshima, Daigo Kobayashi
1Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Abstract:
Highly regulated folding of plasmid DNA (pDNA) through polyion complexation with the synthetic block catiomer, poly(ethylene glycol)-block-poly(L-lysine) (PEG-PLys), was found to occur in such a way that rod structures are formed with a quantized length of 1/2(n + 1) of the original pDNA length folding by n times. The folding process of pDNA was elucidated with regard to rigidity of the double-stranded DNA structure and topological restriction of the supercoiled closed-circular form, and a mechanism based on Euler's buckling theory was proposed. Folded pDNA exhibited higher gene expression efficiency compared to naked pDNA in a cell-free transcription/translation assay system, indicating that the packaging of pDNA into a polyion complex core surrounded by a PEG palisade is a promising strategy for constructing nonviral gene carrier systems. Extension of this finding may provide a reasonable model to further understand the packaging mechanism of supercoiled DNA structures in nature.
