Changes in non-histone chromatin proteins during the storage of chromatin

We have described here the changes in stored chicken reticulocyte chromatin which take place among non-histone protein fractions based on SDS-polyacylamide gel electrophoresis and hybridization of globin cDNA with RNAs transcribed on native and reconstitited chromatin templates.     

The selective participation of brain-specific non-histone proteins of chromatin Np-3,5 during the reproduction of a defensive habit to food in edible snails]

The role of brain-specific nonhistone proteins of chromatine Np-3.5 in the processes of reproduction of elaborated defensive habit to food was studied in previously learning snails. It was found, that gamma-globulines to Np-3.5 during tens of minutes inhibited behavioural and neuronal reactions elicited by a definite conditioned stimulus--carrot juice, without changing reactions to other conditioned stimulus--apple juice. gamma-globulines to other nonhistone proteins of chromatine did not influence the reproduction of food rejection habits. It was supposed that brain-specific nonhistone proteins of chromatine Np-3.5 were selectively involved in the molecular processes providing for neurophysiological mechanisms of information extraction from the long-term memory.     

Immunochemical study of chromatin non-histone proteins

Summary Rabbit antibodies against rat thymus and liver chromatin are obtained. Antithymus IgG are found to interact only with homologous chromatin, while antiliver IgG interact with both liver and thymus chromatin. After preincubation of antiliver IgG with thymus chromatin the antibodies interact with homologous chromatin only. Thus chromatin of both organs contains tissue-specific proteins. Antiliver and antithymus IgG are used to investigate a distribution of tissue-specific and tissue-non-specific immunogenic proteins in thymocyte nuclei. It is shown that these proteins are practically lacking in nuclear membranes, matrix, nuclear sap, nucleous chromatin and do not participate in attaching DNA to the nuclear matrix.Abbreviations NHP non-histone chromatin proteins - IgG immunoglobulins G - PMSF PhMeSO₃     

Lectin activity of chromatin non-histone proteins

Non-histone proteins from chromatin of sea urchin embryos were found to possess the ability to agglutinate erythrocytes.     

Role of non-histone proteins in chromatin solubility

Treatment of chromatin gel with low ionic strength solution of tRNA has produced the dioxyribonucleoprotein (dnptRNA) in which only part of non-histone proteins was removed without loss of any major histone fraction. The solubility of DNP in the presence of 0.15 M NaCl and 1 to 5 mM MgCl2 was considerably higher than that of initial untreated chromatin. It has been assumed that the solubility of chromatin depended primarily on some non-histone proteins and not on H1 histone.     

Interactions of non-histone proteins with immobilized components of chromatin

The specific interaction between non-histone proteins (NHP) of rat thymus and the dextran-immobilized components of chromatin has been investigated. DNA's from E. coli and rat thymus, total histone and reconstituted nucleohistone were used as the affinity sorbents. The distribution of protein fractions in the NHP groups dissociated from chromatin with different ionic strengths was studied by binding on the columns and by SDS-PAAG-electrophoresis. It is shown that NHP of chromatin include the protein components with selective affinity to nucleohistone. These results are discussed in connection with the different functions of NHP in chromatin.     

Growth-related changes of non-histone chromatin proteins from Kirkman-Robbins hepatoma

1. Non-histone chromatin protein fractions NHCP1 and NHCP2 eluted from hydroxyapatite with 50 and 100 mM phosphate buffer (pH 6.8) from nuclei of Kirkman-Robbins hepatoma from 4th, 7th and 9th day of growth were analysed by one- and two-dimensional gel electrophoresis as well as Western blot technique in the presence of antibodies elicited against NHCP1, NHCP2 and dehistonized chromatin of hamster hepatoma and liver. 2. The presence of electrophoretically and immunologically specific components among NHCP1 and NHCP2 fractions during Kirkman-Robbins hepatoma growth was stated.     

Molecular characterization of non-histone chromatin proteins from experimental tumours

Using two-dimensional (2-D) electrophoresis, two non-histone chromatin protein fractions (NHCP1 and NHCP2) from three animal tumours (Kirkman-Robbins hepatoma, Morris hepatoma 7777 and Ehrlich ascites cells) and normal hamster liver were analyzed. Apart from many common components several tissue specific polypeptides of the NHCP1 and NHCP2 fractions were detected. It was found that some spots present in electropherograms of non-histone proteins of tumour cells (M X 10(-3)/pI): 17-24/4.9-6.5 (NHCP1 and NHCP2); 34-41/4.9-6.0 (HCP1 and NHCP2); 44-46/5.3-7.5 (HCP2); 46-49/5.0-7.5 (NHCP1); 49/5.9-7.5 (NHCP2) and 102-134/5.6-7.0 (NHCP1) were absent from normal liver.