Analysis of chromatin reconstitution

Journal Article · Tue Feb 20 04:00:00 EST 1979 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00571a017· OSTI ID:6296062

Fulmer, A W; Fasman, G D

The ability of high molecular weight chicken erythrocyte chromatin to spontaneously self-assemble into native-like material, after dissociation by high ionic strength and reassociation by salt gradient dialysis, was critically examined. The native conformational state of the reassembled nucleoprotein complex was regenerated to the extent reflected by circular dichroism spectra and the thermally induced helix--coil transition of the nucleoprotein DNA. However, the internucleosomal packing of approx. 250 base pairs of DNA per repeating unit, as probed by digestion with micrococcal nuclease, was not regenerated upon reassembly and was replaced by a packing of approx. 160 base pairs per repeating unit. Thus, high molecular weight chromatin containing only lysine-rich histones (H1 and H5) and core histones (H2A, H2B, H3, and H4) is not a true self-assembling system in vitro using the salt gradient dialysis system used herein. Circular dichroism and thermal denaturation studies on core chromatin (lysine-rich histones removed) showed that core histones alone are not capable of reassembling high molecular weight DNA into native-like core particles at low temperature (4/sup 0/C). Reassembly at 21/sup 0/C restored the circular dichroism but not the thermal denaturation properties to those characteristic of undissociated ore chromatin. Nonetheless, micrococcal nuclease digestions of both reassembled core chromatin products were identical with undissociated native core chromatin. Reassembly in the presence of the complete complement of histones, followed by removal of the lysine-rich histones, did regenerate the thermal denaturation properties of undissociated native core particles. These results indicated multiple functions of the lysine-rich histones in the in vitro assembly of high molecular weight chromatin.

• Research Organization: Brandeis Univ., Waltham, MA
• OSTI ID: 6296062
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 18:4; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHEMICAL ANALYSIS
CHROMATIN
DATA
DATA FORMS
DICHROISM
DNA
ENZYMES
ERYTHROCYTES
EXPERIMENTAL DATA
GRAPHS
HISTONES
INFORMATION
KINETICS
MOLECULAR WEIGHT
NUCLEASES
NUCLEIC ACIDS
NUCLEOPROTEINS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOSPHOTRANSFERASES
PROTEINS
REACTION KINETICS
SPECTRA
TRANSFERASES