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I Lasters

Publications and source records attributed to I Lasters.

43 records · Page 3Linked to original sources
PubMed1981

Differences in rearrangements of H1 and H5 in chicken erythrocyte chromatin.

H1 can rearrange in chicken erythrocyte polynucleosomes in 80 mM NaCl buffers. These rearrangements have been studied by sedimentation analysis. H1 redistributes between polynucleosomes as well as between polynucleosomes and monosomes. In these rearrangements H1 molecules move to free DNA sites. In contrast to H1, the chicken erythrocyte specific lysine-rich histone H5 does not show any of these dynamic properties. This difference in mobility of H1 and H5 also manifests itself in the selective extraction of H1 from H1, H5 containing polynucleosomes by the cation-exchange resin AG 50W-X2 at 80 mM NaCl.

Animals↗
PubMed1980

Upon the observation of superbeads in chromatin.

There exist some indications that nucleases recognize "superbeads" in chromatin. We show that a chromatin extract of rat liver which contains so-called "superbead"-peaks can be separated in a Mg++ soluble and a Mg++ insoluble fraction. The Mg++ insoluble fraction contains the full complement of histones and the expected DNA fragments, but has lost the characteristic peaks in sucrosegradient profiles. These discrete peaks are found in the Mg2+ soluble fraction of the chromatin extract. We give evidence that these peaks are RNP particles on the basis of their protein- and nucleic acid contents.

Animals↗
PubMed1980

Histone H1 can be removed selectively from chicken erythrocyte chromatin at near physiological conditions.

Histone H1 was depleted selectively from chicken erythrocyte polynucleosomes, without any detectable concomitant loss of H5 or core particle histones. The depletion is performed with ion exchange resin at low ionic strength (80 mM NaCl). The nucleosomes did not slide during the procedure. In contrast to the native chromatin, H1 depleted polynucleosomes are completely soluble in the 5--600 mM NaCl range.

Animals↗
PubMed1978

Cross-linking of nucleosomal histones with monofunctional imidoesters.

Cross-linking experiments with the MONOfunctional imidoester methyl-acetimidate, in the pH range 7.0 - 8.0, on rat liver nucleosomes generate a cross-linking pattern almost identical with the one observed for much longer BIfunctional reagents (e.g. dimethylsuberimidate). Combined cross-linking and trypsin digestion experiments suggest that all or at least the great majority of this cross-linking occurs on trypsin digestible segments (or "tails") of the histones. The formation of oligomers over such extremely short distances and especially the observation of an H3 homodimer suggests a very close proximity of half-nucleosomes.

Animals↗