AI Article Synopsis
- Understanding chromatin structure is crucial for grasping gene function, as its organization varies throughout the cell cycle and affects compaction levels.
- This study models chromatin as solenoids made up of cylindrical or spherical nucleosomes arranged helically, and examines how changes in their chiral parameters influence chromatin compaction.
- Using discrete dipole approximation (DDA), the research shows how the angular behavior of light scattering can indicate these structural changes, potentially offering a new method for analyzing chromatin and other chiral polymers without labels.
Article Abstract
Understanding the structural organization of chromatin is essential to comprehend the gene functions. The chromatin organization changes in the cell cycle, and it conforms to various compaction levels. We investigated a chromatin solenoid model with nucleosomes shaped as cylindrical units arranged in a helical array. The solenoid with spherical-shaped nucleosomes was also modeled. The changes in chiral structural parameters of solenoid induced different compaction levels of chromatin fiber. We calculated the angle-resolved scattering of circularly polarized light to probe the changes in the organization of chromatin fiber in response to the changes in its chiral parameters. The electromagnetic scattering calculations were performed using discrete dipole approximation (DDA). In the chromatin structure, nucleosomes have internal interactions that affect chromatin compaction. The merit of performing computations with DDA is that it takes into account the internal interactions. We demonstrated sensitivity of the scattering signal's angular behavior to the changes in these chiral parameters: pitch, radius, the handedness of solenoid, number of solenoid turns, the orientation of solenoid, the orientation of nucleosomes, number of nucleosomes, and shape of nucleosomes. These scattering calculations can potentially benefit applying a label-free polarized-light-based approach to characterize chromatin DNA and chiral polymers at the nanoscale level.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8512730 | PMC |
| http://dx.doi.org/10.3390/polym13193422 | DOI Listing |
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