Loosening of DNA/Polycation Complexes by Synthetic Polyampholyte to Improve the Transcription Efficiency: Effect of Charge Balance in the Polyampholyte

Abstract

High mobililty group proteins are amphoteric nuclear proteins that are known to unfold chromatin to stimulate transcription. To mimic their structures, we synthesized the novel polyethylene glycol (PEG) derivatives, PEG-ACs, consisting of both amino- and carboxyl-pendants in various ratios, and their loosening and transcription-improving activity on the DNA complex was examined. Fluorescence anisotropy measurement revealed that anionic PEG-ACs with more carboxyls than amines could efficiently loosen the DNA/polyethyleneimine complex. Those anionic PEG-ACs showing a loosening effect on the DNA complex evidently increased the transcription rate to >20 times higher than that of the original complex, probably owing to the facilitated approach of transcriptional factors to the DNA segments in the loosened complexes. The complexes with anionic PEG-ACs also showed improved transgene expression level on the cultured cells, indicating the effectiveness of improving transcriptional activity to attain a high extragene expression by the plasmid complex. The loosening mechanism of DNA/polycation complexes was investigated with a simplified model via Monte Carlo simulation to discern the difference in the presence of cationic polyampholytes, anionic polyampholytes, and polyanions.

Antitumor effect of chondroitin sulfate‐coated ternary granulocyte macrophage‐colony‐stimulating factor plasmid complex for ovarian cancer

“…Regarding the size after the polymer processing being small, it is suggested to be advantageous for uptake in the cell after attachment to the CD44 receptor on the cell membrane. Furthermore, as we reported previously , addition of polyanions, such as HA and polyethylene glycol derivatives, to the DNA/polycation complex caused the loosening of the complex particles and improved transcription efficiency by the effect of the charge balance in the polyampholyte. The addition of CS would thus also loosen the complex.…”

Aliphatic Polyethers: Classical Polymers for the 21st Century

“…The introduction of allyl or vinyl moieties via allyl glycidyl ether (AGE) or vinyloxy ethyl glycidyl ether (EVGE) enables further reactions, e.g., through thiol‐ene addition to attach biomolecules or through hydrosilylation enabling the synthesis of complex architectures …”

Multifunctional Poly(ethylene glycol)s

“…[74,75] Appropriate comonomers provide an inherent functional group-to date only the direct introduction (i.e. avoiding protective groups) of allyl groups has been realized [58,[76][77][78][79][80][81][82][83][84][85] that is accessible by post-polymerization modification by two different routes: 1) removal of a protective group and/or 2) further organic transformation steps. Crucial requirements for a suitable protective group are stability under the harsh basic conditions of the anionic polymerization, few chain transfer reactions, and facile cleavage after the polymerization.…”