An atomic force microscope was used to image and stretch single synthetic chromatin fibers consisting of twelve core nucleosomes with no linker histones. Peaks in the force-curves are attributed to sequential detachment of nucleosomes from the glass support. The short distances between peaks and reversibility of the pulling process show that the nucleosomes remain intact even at tensions on the order of 350 picoNewtons (pN). This is more than an order of magnitude larger than the force required to de-spool histone octamers from the nucleosomal DNA in laser optical tweezer measurements made with longer molecules, suggesting that loading rates and the length of the molecule are important factors in determining the force required to break inter-molecular bonds.
|Original language||English (US)|
|Number of pages||8|
|State||Published - 2000|
ASJC Scopus subject areas
- Molecular Biology
- Biochemistry, Genetics and Molecular Biology(all)
- Clinical Biochemistry