Spontaneous formation of liquid crystalline phases and phase transitions in highly concentrated plasmid DNA
Journal article, 2011

The liquid crystalline (LC) properties of two supercoiled plasmid DNA samples, pBSK (2958 bp) and pGEM (3000 bp), have been studied using polarised light microscopy (PLM), circular dichroism (CD) and UV-Vis spectroscopy. The influence of methods of isolation on plasmid LC behaviour is described, and using PLM we have demonstrated the spontaneous formation of cholesteric fingerprint-like textures. Preliminary studies of LC phase transitions in pGEM show the irreversibility of LC phase formation, as a consequence of changes in the tertiary structure of supercoiled plasmids. Using UV-Vis spectroscopy a hyperchromic effect was observed with increasing temperature. The CD spectra clearly showed structural changes, and probably mismatching of DNA bases, during cooling. Finally, we have observed an irreversible phase transition in plasmid DNA which is very different from that previously reported in linear DNA.

hyperchromic effect

bacteria

supercoiled dna

dimensions

thermal-denaturation

DNA

linking

escherichia-coli

cholesteric phase

microscopy

phase transition

growth temperature

plasmid DNA

supercoiling

nucleic acids

shock

fingerprint-like texture

liquid crystal

isolation techniques

circular dichroism

Author

Piotr Hanczyc

Chalmers, Chemical and Biological Engineering, Physical Chemistry

K. Matczyszyn

Wrocław University of Science and Technology

K. Pawlik

Polish Academy of Sciences

AKademia Medyczna Wroclawiu

J. Olesiak

Wrocław University of Science and Technology

H. Leh

Laboratoire de Biologie et de Pharmacologie Appliquee

M. Buckle

Laboratoire de Biologie et de Pharmacologie Appliquee

Liquid Crystals

0267-8292 (ISSN) 1366-5855 (eISSN)

Vol. 38 4 461-468

Subject Categories

Chemical Sciences

DOI

10.1080/02678292.2011.552740

More information

Latest update

10/30/2018