Sodium butyrate induced structural changes in HeLa cell chromatin

Journal Article · Tue Mar 02 00:00:00 EST 1982 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00534a026· OSTI ID:5530414

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 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., Walthan, MA
• DOE Contract Number: EP-78-S-02-4962.A000
• OSTI ID: 5530414
• Journal Information: Biochemistry; (United States), Vol. 21:5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ACETYLATION
BIOLOGICAL EFFECTS
CHROMATIN
ULTRASTRUCTURAL CHANGES
BUTYRIC ACID
EDTA
HELA CELLS
HISTONES
MOLECULAR WEIGHT
PH VALUE
SODIUM COMPOUNDS
THERMAL DEGRADATION
ACYLATION
ALKALI METAL COMPOUNDS
AMINO ACIDS
CARBOXYLIC ACIDS
CHELATING AGENTS
CHEMICAL REACTIONS
MONOCARBOXYLIC ACIDS
MORPHOLOGICAL CHANGES
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
550200* - Biochemistry