Thermal stability of nucleosomes studied in situ by flow cytometry: Effect of ionic strength and n-butyrate Journal Article


Authors: Darzynkiewicz, Z.; Carter, S. P.
Article Title: Thermal stability of nucleosomes studied in situ by flow cytometry: Effect of ionic strength and n-butyrate
Abstract: Heating of cells permeabilized with ethanol and resuspended in aqueous media increases accessibility of DNA to intercalating dyes such as acridine orange (AO). The curves, representing increase in binding of AO as a function of rise in temperature, indicate that the transitions are cooperative. The transitions are sensitive to ionic strength and occur at lower temperatures when cells are suspended in media of increasing ionic strength. Extraction of histones raises accessibility of DNA to intercalators at room temperature, and heating has little effect on additional binding. The results are interpreted as indicating thermal destruction of nucleosomal structure in nuclear chromatin; dissociation of DNA from core histones results in its increasing ability to intercalate AO, most likely due to increased topological freedom to undergo unwinding and elongation following binding of the intercalator. Preincubation of cells with n-butyrate, known to induce histone hyperacetylation, lowers the heat stability of nucleosomes by about 5 °C. On the other hand, no differences are observed between chromatin of mitotic vs interphase cells tested over a wide range of ionic strengths (0.1-0.7 N NaCl). The method appears to be useful as a probe of chromatin structure at the nucleosomal level. © 1989.
Keywords: nonhuman; flow cytometry; mitosis; animal cell; mouse; animal; mice; animalia; cell culture; histone; chromatin; thermodynamics; acridine orange; thermostability; butyric acid; staining and labeling; nucleosome; nucleosomes; butyric acids; ionic strength; butyrates; leukemia l1210; osmolar concentration; priority journal; support, u.s. gov't, p.h.s.; preliminary communication
Journal Title: Experimental Cell Research
Volume: 180
Issue: 2
ISSN: 0014-4827
Publisher: Elsevier Inc.  
Date Published: 1989-02-01
Start Page: 551
End Page: 556
Language: English
DOI: 10.1016/0014-4827(89)90082-7
PUBMED: 2464501
PROVIDER: scopus
DOI/URL:
Notes: Article -- Export Date: 14 April 2020 -- Source: Scopus
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