Elucidation of conformational hysteresis on a giant DNA.
The conformational behavior of a giant DNA mediated by condensing agents in the bulk solution has been investigated through experimental and theoretical approaches. Experimentally, a pronounced conformational hysteresis is observed for folding and unfolding processes, by increasing and decreasing the concentration of condensing agent (polyethylene glycol) (PEG), respectively. To elucidate the observed hysteresis, a semiflexible chain model is studied by using Monte Carlo simulations for the coil-globule transition. In the simulations, the hysteresis loop emerges for stiff enough chains, indicating distinct pathways for folding and unfolding processes. Also, our results show that globular state is thermodynamically more stable than coiled state in the hysteresis loop. Our findings suggest that increasing chain stiffness may reduce the chain conformations relevant to the folding pathway, which impedes the folding process.
Shew
Chwen-Yang
CY
Department of Chemistry, College of Staten Island and Graduate Center, City University of New York, 2800 Victory Boulevard, Staten Island, New York 10314, USA. shew@mail.csi.cuny.edu
Higuchi
Yuji
Y
Yoshikawa
Kenichi
K
D017122:Bacteriophage T4 / Q000737:chemistry*; D003198:Computer Simulation; D004279:DNA, Viral / Q000737:chemistry*; D009010:Monte Carlo Method; D009690:Nucleic Acid Conformation
D004279:DNA, Viral