We analyse the effects of the environment (solvent quality, presence of extended structures — crowded environment) that may have impact on the order of the transition between denaturated and bounded DNA states and lead to changes in the scaling laws that govern conformational properties of DNA strands. We find that the effects studied significantly influence the strength of the first order transition. To this end, we re-consider the Poland-Scheraga model and apply a polymer field theory to calculate entropic exponents associated with the denaturated loop distribution. For the d= 3 case, the corresponding diverging ε = 4 d expansions are evaluated by restoring their convergence via the resummation technique. For the space dimension d= 2, the exponents are deduced from mapping the polymer model onto a two-dimensional random lattice, i.e., in the presence of quantum gravity. We also show that the first order transition is further strengthened by the presence of extended impenetrable regions in a solvent that restrict the number of the macromolecule configurations.
Bibliographical noteFunding Information:
We acknowledge useful discussions with Maxym Dudka, Ralph Kenna, Mariana Krasnytska, and Dmytro Shapoval. This work was supported in part by the National Academy of Sciences of Ukraine, project KPKBK 6541230.
- crowded environment
- DNA denaturation
- Poland-Scheraga model
- polymer networks
ASJC Scopus subject areas
- Condensed Matter Physics
- Physics and Astronomy (miscellaneous)