Magnetic Resonance Studies of Deoxyribonucleoprotein

  title={Magnetic Resonance Studies of Deoxyribonucleoprotein},
  author={E. Bradbury and B. Carpenter and H. Rattle},
THE structure of chromatin, and the problems of organizing large lengths of DNA within the cell nucleus, are currently of considerable interest. It now appears established that the agents of chromosome structure are the histones found in conjunction with DNA in the chromosome, which may also act at some stage of genetic regulation. Of the five major types of histone fraction normally associated with mammalian genetic material, the lysine-rich histone F1 (or histone I) has some properties which… Expand
Histones, chromatin structure, and control of cell division.
The phosphorylation of H1 is involved in the initial steps of chromosome condensation and that the cyclical variation in enzyme activity is an important factor in the control of cell division. Expand
Utilization of neutron scattering for analysis of chromatin and nucleoprotein structure.
This chapter discusses the use of neutron scattering for analysis of chromatin and nucleoprotein structure and interprets the results in terms of the arrangement of the subunits within the chromatin fiber. Expand
Magnesium binding and conformational change of DNA in chromatin.
The ellipticity of chromatin shows a smaller decrease relative to the other nucleoproteins and protein-free DNA upon the addition of Mg2+ ions, apparently somewhat protected against the conformational change induced by these ions. Expand
Involvement of histone H1 in the organization of the nucleosome and of the salt-dependent superstructures of chromatin
It is concluded that H1 stabilizes the nucleosome and is located in the region of the exit and entry points of the DNA in H1-depleted chromatin, which has the form of an unravelled filament. Expand
Deoxyribonuclease II as a probe for chromatin structure. II. Mode of cleavage.
A mechanism for DNAase II cleavage of chromatin in the 200-bp and 100-bp modes is proposed and discussed in the context of structural features of Chromatin recognized byDNAase II. Expand
Conformation studies of histone H1(0) in comparison with histones H1 and H5.
Considerable interest attaches to the findings that another type of mammalian lysine-rich histone H1(0) has an apolar region exhibiting considerable sequence homology with the central globular region of H5. Expand
Conformational changes in subfractions of calf thymus histone H1.
In salt-free solutions, each of the four major subfractions show very little change in conformation in going from low to neutral pH, but each shows a very sharp transition near pH 9.5, which gives rise to a marked increase in fluorescence anisotropy and fluorescence intensity, and involves the formation of both alpha and beta strucute in a manner similar to that of the salt-induced state. Expand
Chromatin Structure and the Role of Histone Phosphorylation in the Cell Cycle
Chromatin contains 3 major components at the molecular level: DNA, histones and non-histones. RNA and, possibly, lipids are present in smaller quantities. Histones are basic proteins strongly boundExpand
Mechanisms of chromatin activation and repression.
The chapter discusses the gene regulation at the different levels at which the activation or repression of chromatin seems to occur—the whole nucleus, the individual chromosome, the large block of genes, and the individual gene locus. Expand
Structural repeating units in chromatin. II. Their isolation and partial characterization.
Chromatin fragments prepared by brief digestion with DNase II or micrococcal nuclease separated into a family of bands on sucrose gradients, suggesting that chromatin is organized into discrete DNA protein units. Expand


Interactions between the lysine-rich histone F1 and deoxyribonucleic acid.
Bivalent cations are shown to be more effective in dissociating the DNA-histone complex and can be selectively removed from deoxyribonucleoprotein with 0.1m-magnesium chloride. Expand
Conformational Investigations of Histones
WE have carried out some investigations into the conformations of whole histones and histone fractions under various conditions. The experiments on repression of DNA-dependent RNA synthesis withExpand
The isolation and properties of deoxyribonucleoprotein particles containing single nucleic acid molecules
Summary A gel-free solution of deoxyribonucleoprotein was prepared in high yield from calf thymus by maintaining the concentration and ionic strength at very low values and by careful homogenization.Expand
The dissociation of chicken erythrocyte deoxyribonuleoprotein and some properties of its partial nucleoproteins.
An analysis of the sedimentation of partial dRNP preparations on sucrose gradients showed that native dR NP consists of DNA molecules each complexed with histone fractions of all types. Expand
Variations in the phosphate content and thiołdisulphide ratio of histones during the cell cycle. Studies with regenerating rat liver and sea urchins.
The phosphorylation of histone F1 in this ;S period' is decreased by gamma-irradiation, but, like phosphate uptake into DNA, is affected to an even greater extent if the irradiation is given in the presynthetic period. Expand
An investigation of the conformational changes in histones F1 and F2a1 by proton magnetic resonance spectroscopy.
High resolution nuclear magnetic resonance spectroscopy is used to study conformational changes in histone fractions F2a1 and F1 when the ionic strength of aqueous solutions is raised and the proportion of amino acid residues incorporated into secondary structure is less than that involved in the conformationalChanges indicated by thenuclear magnetic resonance results. Expand
Simple computer-aided approach for the analyses of the nuclear-magnetic-resonance spectra of histones. Fractions F1, Fsa1, F2B, cleaved halves of F2B and F2B-DNA.
A simple method for the computer simulation of high-resolution nuclear magnetic resonance spectra is described and applied to the analyses of salt-induced changes in the spectra of histones, which allows the information contained in the spectral envelope to be used and has led to some modifications of the earlier proposals of the segments of histone involved in salt- induced conformational changes, interhistone interactions and interactions with DNA. Expand
Thymus deoxyribonucleoprotein. III. Sedimentation behaviour.
It was concluded that within any one molecule of deoxyribonucleoprotein there is a range of stability of binding of the histone protein to the DNA. Expand
The role of lysine-rich histone in the maintenance of chromatin structure in metaphase chromosomes.
Evidence is presented that in metaphase chromosomes, too, chromatin threads are held together by lysine-rich histones. Expand
The electrophoresis of histones in polyacrylamide gel and their quantitative determination.
  • E. W. Johns
  • Medicine, Chemistry
  • The Biochemical journal
  • 1967
A method has been developed for the quantitative determination of the separated histone fractions by measuring the colour yields of dye-histone complexes formed in the gel, and the relative mobilities with respect to a marker protein, bovine plasma albumin. Expand