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L Srebreva

Publications and source records attributed to L Srebreva.

17 recordsLinked to original sources
PubMed1993

Histone H1 deposition and histone-DNA interactions in replicating chromatin.

An immunochemical method for analyzing protein interactions with BrdUrd-substituted DNA was used to study binding of histones to nascent DNA in nuclei. The results indicate that in Ehrlich ascites tumor (EAT) cells, histone H1 deposits on newly replicated DNA simultaneously with or immediately after core histone deposition so that in chromatin replicated for 3 min, the stoichiometry of the histones is the same as in bulk chromatin. All histones, and especially histone H1, interact with nascent DNA more weakly than with bulk chromatin, although the efficiency of interaction via the globular domains seems to be the same for both types of chromatin.

Animals↗
PubMed1991

Purification of histone H10 and its subfractions under non-denaturing conditions.

A quick and convenient method for a non-denaturing purification of histone H10 and its subfractions from different mammalian sources is presented. It is based on cation-exchange chromatography on a CM-Sephadex C-25 column developed by a linear gradient of NaCl. The procedure allows a satisfactory fractionation of H10 subfractions in a form suitable for further studies in assays requiring the native state of the protein.

Animals↗
PubMed1991

The occurrence and properties of histone H1 zero in quiescent rabbit tissues.

1. The issue of the existence and the properties of histone H1 zero in quiescent rabbit tissues was approached by electrophoretic, chromatographic and immunochemical techniques. 2. The results demonstrated that the rabbit tissues did contain a typical histone H1 zero, its properties being comparable to those of H1 zero from all other sources studied thus far.

Animals↗
PubMed1990

Interaction of histones H1 and H1(0) with superhelical and linear DNA.

By using direct competition experiments, the binding of histone H1AB (a mixture of H1A and H1B) and H1(0) to superhelical and linear DNA forms was studied. Mouse liver H1 isohistones and plasmid p alpha GD containing part of the 5' flanking and part of the coding sequence of the mouse alpha-globin gene in pUC18 were used as partners in the binding reaction. The competition experiments were performed by direct mixing of the histone with labelled supercoiled DNA (at 125 mM NaCl and at a histone/DNA ratio of 1.0) and addition to the mixture of increasing amounts of cold competitor DNA, either supercoiled or linear. The radioactivity of the complex formed was determined by filter binding. The results show that both histones H1 and H1(0) posses a strong binding preference for supercoiled DNA forms. Thus, histone H1(0) resembles the regular somatic set of histone H1 and not the other differentiation-specific histone H5 studied thus far.

Animals↗
PubMed1989

Accessibility of histone H1(0) and its structural domains to antibody binding in mononucleosomes.

This work is devoted to the study of the immunoreactivity of histone H1(0) and its major structural domains in mononucleosomes. Three types of antibody populations were used: (i) anti-H1(0) which reacted with antigenic determinants situated along the whole polypeptide chain; (ii) anti-GH5 which recognized epitopes located in the globular region; and (iii) anti-C-tail antibodies reacting specifically with fragment 99-193 of the protein molecule. The anti-GH5 antibodies gave a weak reaction, the C-tail-specific antibodies reacted relatively strongly and the antiserum to the intact molecule showed an intermediate level of reactivity. The relative intensities of the immunoreaction could be interpreted as reflecting the exposure of the antigenic determinants of the individual protein domains in the monosome particle.

Animals↗
PubMed1989

Protein A in the stable L-forms of Staphylococcus aureus.

The presence of protein A in the stable L-form of S. aureus BM 3041 was proved. Its amino acid composition and electrophoretic characteristics were compared with the parent strain. The location of protein A on the cytoplasmic membranes of the L-form cells, as well as on the extracellular membranes were established by immunoelectron microscopy. In the cells of the parent bacterium its location on the cell wall was observed.

Amino Acids↗
PubMed1988

Immunofluorescent localization of histone H10 in the nuclei of proliferating and differentiating Friend cells.

By using affinity-purified antibodies to H10 and to H1AB the localization of these histones was studied by indirect immunofluorescence in the nuclei of proliferating (EAT and uninduced Friend cells) and of differentiating (induced Friend cells) cell populations. While with H1AB antibodies a bright fluorescence all over the chromatin was obtained, the localization of H10 varied depending on the state of the cell population. In the proliferating EAT cells it was localized strictly in the nucleoli. The Friend cell population revealed a heterogeneous picture with two types of H10 localization-nucleolar predominating in uninduced cell populations and peripheral predominating in induced cells. A comparison with literature data suggests that H10 seems to be associated with chromatin regions containing active genes.

Animals↗
PubMed1987

Immunological evidence for the existence of H1-like histone in yeast.

In view of the controversies about the existence of histone H1 in yeast we have reinvestigated the problem by studying yeast proteins extracted with perchloric acid and salt. Perchloric-acid-extracted proteins from whole cells contain only two fractions which comigrate with 'authentic' yeast high-mobility-group proteins (HMG) in both SDS and acid urea gels. These extracts show a considerable cross-reaction with anti-(calf thymus HMG) antiserum and do not react with antiserum to mouse liver H1. The isolation of 'authentic' yeast HMG by the standard salt/trichloroacetic acid procedure gives two types of preparations containing different numbers of protein bands. The poorer preparation reacts only with the anti-HMG antiserum whereas the richer preparation also gives considerable cross-reaction with the anti-H1 antiserum. Immunoblotting analysis performed on the salt-extracted proteins reveals the presence of three protein bands giving positive immunoreaction with the anti-H1 antiserum. The immunoreactive bands have electrophoretic mobilities close to that of the marker calf thymus H1 and similar to the mobilities of the presumptive yeast H1 fractions found by other authors.

Animals↗
PubMed1986

Specificity studies on anti-histone H1 antibodies obtained by different immunization methods.

Antibodies were elicited against chromatographically purified histone H1 subfractions or against their complexes with RNA and their specificity studied by enzyme-linked immunosorbent assay. The results show that complexing of the pure protein with RNA does not lead to any significant increase in the antibody titer and results in obtaining antibodies predominantly against the common antigenic determinants present in the H1 histone class. On the other hand, using pure histone fractions for immunization gives rise to antibody populations reacting mainly with the subfraction-specific determinants on the histone molecule. In view of these results the literature data should be interpreted with caution.

Animals↗
PubMed1984

Histone H1o in developing rat brain cells.

Histone H1o was found both in neuronal and oligodendrocyte rat-brain nuclei fractionated by sucrose-gradient isopycnic centrifugation. This histone was absent during the early stages of development when the brain cells were still proliferating, but it appeared in significant amounts in the terminally differentiated cells.

Aging↗
PubMed1983

Occurrence of histone H10-related protein fraction in trout liver.

The lysine-rich histones of trout liver were studied in order to see whether a protein similar to mammalian histone H1(0) exists in this lower vertebrate. The biochemical methods used involved SDS and acid-urea polyacrylamide gel electrophoresis, gel exclusion and ion-exchange chromatography. Specific rabbit antibodies were elicited against chromatographically-purified mouse liver H1(0) and applied for further characterization of the presumptive trout-liver H1(0) fraction. The results from the indirect immunofluorescence on nitrocellulose-immobilized crude H1 subfractions and from the complement fixation test supplied additional evidence for the existence of an H1(0)-like protein in trout liver.

Animals↗
PubMed1983

Dynamics of H1(0) content in rat liver after partial hepatectomy.

The changes in the lysine-rich histone subfraction H1(0) have been quantitatively studied in rat liver during the regeneration period after partial hepatectomy. A gradual decrease in this protein was found early after operation with a minimal value around the time of maximal mitotic activity. The reduction in the H1(0) content paralleled well the increasing number of cells in the cell cycle.

Animals↗