Structure of Chromatin DNA not Complexed with Protein

Abstract Rat liver chromatin was titrated by poly-ᴅ-lysine of mol.wt. 140,000. Approximately 32% of the phosphate groups of the chromatin were found to react with the polycation. By submitting the chromatin-poly-ᴅ-lysine complex to pronase and DNase I digestion and by further submitting the obtained DNA-lysine complex to hydroxy-apatite-chromatography, "free" DNA was isolated. The mean S-value of this DNA was found to be 10 ± 0 .8 , corresponding to approximately 2100 nucleo tide pairs, its renaturation kinetics similar to total DNA. On the basis of these results and on the findings that histone-saturated DNA-histone recombinates are digested with DNase I up to 65% a model of chromatin structure was proposed, taking into account protein covered-and free DNA regions

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Early alterations in rat liver chromatin structure after a single dose of diethylnitrosamine

Bioscience Reports ◽

10.1007/bf01121950 ◽

1983 ◽

Vol 3 (2) ◽

pp. 185-188

Author(s):

Karl Letnansky ◽

Hratschik R. Vardapetjan

Keyword(s):

Single Dose ◽

Rat Liver ◽

Chromatin Structure ◽

Chemical Modifications ◽

Lower Melting ◽

Melting Temperatures ◽

Liver Chromatin ◽

Rat Livers ◽

Rapid Shift ◽

Good Agreement

In the chromatin of 24-h regenerating rat livers, derivative melting profiles are characterized by a high proportion of transitions above 90°C. After the injection of diethylnitrosamine there is a rapid shift to lower melting temperatures. This is due to a rearrangement of the chromatin to higher amounts of nucleosomal components but possibly also a consequence of chemical modifications and conformational alterations of the DNA. In the nonregenerating liver essentially the same observations can be made, although reactions proceed significantly slower. These results are in good agreement with the observation that carcinogens are more active in tissues stimulated to rapid proliferation as compared to resting tissues.

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Lectins as probes of chromatin structure. Binding of concanavalin A to purified rat liver chromatin.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)66934-6 ◽

1977 ◽

Vol 252 (20) ◽

pp. 7062-7067

Author(s):

W B Rizzo ◽

M Bustin

Keyword(s):

Rat Liver ◽

Concanavalin A ◽

Chromatin Structure ◽

Liver Chromatin

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Thiol proteins in chromatin

Bioscience Reports ◽

10.1007/bf01115154 ◽

1986 ◽

Vol 6 (3) ◽

pp. 257-263

Author(s):

Anna Ferraro ◽

Anna Giartosio ◽

Margherita Eufemi ◽

Donatella Barra ◽

Fabio Altieri ◽

...

Keyword(s):

Chromatin Structure ◽

Dnase I ◽

Structure And Function ◽

Thiol Groups ◽

Pig Liver ◽

Dnase Ii ◽

Liver Chromatin ◽

Chromatin Proteins ◽

And Function ◽

Reduced State

Total half-cystine residues in proteins of pig liver chromatin have been measured. About half of them are present in the reduced state. Thiol groups of non-historic chromatin proteins, which amount to about 40 nmol/mg of protein, are preferentially located in chromatin fragments which are more easily solubilised either by DNAse I or by DNAse II. The data obtained are compatible with an involvement of SH and SS groups in chromatin structure and function.

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