Electrostatic background of chromatin fiber stretching.
We have carried out an investigation of the electrostatic forces involved in gradual removal of the DNA from the histone proteins in chromatin. Two simple models of DNA-histone core dissociation were considered. Calculations of the electrostatic free energy within the Poisson-Boltzmann theory gave similar results for the both models, which turned out to be in a qualitative agreement with recent optical tweezers stretching experiments measuring the force necessary to unwrap DNA from the histone core. Our analysis shows that the electrostatic interactions between the highly negatively charged polymeric DNA and the positively charged histones play a determining role in stabilizing the nucleosomes at physiological conditions.
School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore. korolev@ntu.edu.sg
Nikolay
N
Korolev
Alexander P
AP
Lyubartsev
Aatto
A
Laaksonen
D002843:Chromatin / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D006657:Histones / Q000737:chemistry; D008024:Ligands; D046911:Macromolecular Substances; D008958:Models, Molecular; D009707:Nucleosomes / Q000737:chemistry; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers; D055672:Static Electricity; D013816:Thermodynamics
D002843:Chromatin; D004247:DNA; D006657:Histones; D008024:Ligands; D046911:Macromolecular Substances; D009707:Nucleosomes; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers