Format

Send to

Choose Destination
Biophys J. 2010 Jul 7;99(1):201-7. doi: 10.1016/j.bpj.2010.04.016.

Thermodynamics of polyethylenimine-DNA binding and DNA condensation.

Author information

1
Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada. ukuniharu@yahoo.ca

Abstract

In this study, polyethylenimine (PEI) binding to DNA was examined by isothermal titration calorimetry. Two types of binding modes were found to describe the interactions between these polyelectrolytes in buffers and in water. One type of binding involves PEI binding to the DNA groove because the enthalpy change of this binding mode is positive, and PEI is deprotonated to bind to DNA. Another likely binding mode involves external binding of PEI to the DNA phosphate backbone, accompanied with DNA condensation. The enthalpy change is negative and PEI is protonated when it binds to DNA in this mode. The intrinsic enthalpy change of first binding mode is 1.1 kJ/mol and -0.88 kJ/mol for the second binding mode. This result implies that the PEI is rearranged from the groove to the phosphate backbone of DNA when DNA is condensed. The mechanism of DNA condensation caused by PEI is discussed in this study.

PMID:
20655848
PMCID:
PMC2895367
DOI:
10.1016/j.bpj.2010.04.016
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center