Sodium butyrate induced structural changes in HeLa cell chromatin

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00534a026· OSTI ID:6173399

Reczek, P R; Weissman, D; Huvos, P E; Fasman, G D

Postsynthetic modifications of core histones by treatment of HeLa S3 cells with 5 mM sodium butyrate lead to alterations in the structure of high molecular weight chromatin. Whole chromatin from butyrate-treated cells, which results in highly acetylated core histones, has an ellipticity (theta)/sub 282.5/ of 3700 deg cm/sup 2/ dmol/sup -1/ (0.2 mM EDTA, pH 7.4) that is 1200 deg cm/sup 2/ dmol/sup -1/ less than chromatin from untreated HeLa cells, suggesting a more condensed structure. No difference in the circular dichroism spectra was observed in Hl-stripped, high molecular weight chromatin obtained from control and butyrate-treated cells at low (0.2 mM EDTA, pH 7.4) ionic strength.Thermal denaturation profiles of high molecular weight chromatin were resolved into three transitions and exhibited a shifting of hyperchromicity from transition I to transition III, at a higher T/sub m/, with butyrate treatment of HeLa cells, further indicating a more compact structure. Thermal denaturation profiles of Hl-stripped chromatin were not affected by butyrate treatment. Ionic strength studies in the range of 0-5 mM NaH/sub 2/PO/sub 4/, 0.2 mM EDTA, pH 7.4, of high molecular weight chromatin exhibited a decrease in (theta)/sub 282.5/ and a shifting of hyperchromicity from transition I to transition III with increasing ionic strength. Control high molecular weight chromatin was more sensitive to changes in ionic strength than its highly acetylated counterpart. These results suggest that acetylation of histones alone does not result in a change in histone-DNA interaction but other changes associated with butyrate treatment most probably cause a more condensed structure, of the fraction studied herein, which is mediated by Hl or other materials removed during stripping in 0.35 M NaCl.

• Research Organization: Brandeis Univ., Waltham, MA
• DOE Contract Number: AC02-78EV04962
• OSTI ID: 6173399
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 21; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
560301 -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACETYLATION
ACYLATION
ALKALI METAL COMPOUNDS
BUTYRIC ACID
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHROMATIN
DICHROISM
HELA CELLS
HISTONES
MOLECULAR WEIGHT
MONOCARBOXYLIC ACIDS
MORPHOLOGICAL CHANGES
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEIN DENATURATION
PROTEINS
SODIUM COMPOUNDS
ULTRASTRUCTURAL CHANGES