Identification of nonhistone chromatin proteins in chromatin subunits.
- 1 October 1976
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 73 (10), 3458-3462
- https://doi.org/10.1073/pnas.73.10.3458
Abstract
Rat liver chromatin was digested by micrococcal nuclease. More than 80% of the enzyme-digested chromatin could be recovered after centrifugation. Treatment with sodium deoxycholate and Triton X-100 at concentrations of 0.5% in the final chromatin suspension gave a higher recovery. Chromatin subunits were fractionated on a 5-30% linear sucrose density gradient. Approximately 35% of the chromatin subunits could be recovered from the gradient. Chromatin subunits and their DNA fragments were identified by gel electrophoresis and ultracentrifugation. The presence of nonhistone chromatin proteins (NHCP) in chromatin subunits was demonstrated by the following criteria: (i) Quantitative analysis showed that the mass ratio of histone to NHCP, in the presence or absence of detergents, was 1:0,25 or 1:0.1, respectively. (ii) After the removal of acid-soluble protein from the subunits, it was found that most of the phenol-soluble NHCP were similar to total chromatin NHCP. However, four major fractions of these phenol-soluble NHCP were found to be enriched in the subunits as identified by two-dimensional polyacrylamide gel electrophoresis. (iii) Experiments using an exchange of isotope-labeled and nonlabeled chromatin showed that NHCP were tightly bound to the chromatin subunits.Keywords
This publication has 34 references indexed in Scilit:
- The subunit structure of sea urchin sperm chromatin: A kinetic approachFEBS Letters, 1975
- Electron microscopic and biochemical evidence that chromatin structure is a repeating unitCell, 1975
- Chromatin Structure: A Repeating Unit of Histones and DNAScience, 1974
- Transcription of chromatin by bacterial RNA polymeraseJournal of Molecular Biology, 1973
- Non-histone proteins and gene activation in regenerating rat liverExperimental Cell Research, 1973
- Chromatin sub-structure. The digestion of chromatin DNA at regularly spaced sites by a nuclear deoxyribonucleaseBiochemical and Biophysical Research Communications, 1973
- Selective dissociation of histones from chromatin by sodium deoxycholateJournal of Molecular Biology, 1971
- Stepwise removal of histones from native deoxyribonucleoprotein by titration with acid at low temperature and some properties of the resulting partial nucleoproteinsJournal of Molecular Biology, 1969
- Organ-specific restriction of transcription in mammalian chromatinJournal of Molecular Biology, 1968
- Effets d'un inhibiteur de la catalase sur la formation induite de cet enzyme chez la levureBiochimica et Biophysica Acta, 1955