Successive elution by ion-exchange chromatography of H3-H4 histone complexes differing in their degree of acetylation.

On Biorex 70 ion exchanger at neutral pH the histones H3 and H4 are usually eluted by 4 M guanidinium chloride (gdm Cl). In order to protect cysteines and methionines from oxidation we systematically added 2-mercaptoethanol to the elution buffer. This resulted in the two histones being unexpectedly eluted together at around 1 M gdm Cl.

Application of electrospray and fast atom bombardment mass spectrometry to the identification of post-translational and other chemical modifications of proteins and peptides.

Mass spectrometry is a very powerful tool in the identification of chemical modifications of proteins and peptides. Often these modifications cannot be determined by conventional techniques. This report describes the combined use of electrospray ionization mass spectrometry and fast atom bombardment mass spectrometry to complete the primary structure of proteins and peptides.

Specificity of antibodies raised against triacetylated histone H4.

Ten monoclonal antibodies (mAbs) were obtained by immunizing animals with triacetylated histone H4 from cuttle-fish. The fine specificity of these antibodies was studied using various populations of acetylated H4, (H3H4)2 tetramers and histone octamers as well as with acetylated and nonacetylated peptides of H4. None of these mAbs were found to recognize triacetylated H4.

Histone H4 from cuttlefish testis is sequentially acetylated. Comparison with acetylation of calf thymus histone H4.

The differently acetylated subfractions of histone H4 isolated from cuttlefish testis and from calf thymus were separated by ion exchange chromatography on sulfopropyl-Sephadex, using a shallow linear gradient of guanidine hydrochloride in the presence of 6 M urea at pH 3.0. The tetra-, tri-, di-, mono-, and nonacetylated forms of cuttlefish H4 represent 2, 6.

Comparison of different methods for localizing antigenic regions in histone H2A.

Four different variations of enzyme-linked immunosorbent assays (ELISA) were used to analyze the antigenic structure of histone H2A. Eleven natural and 10 synthetic peptides of H2A were tested for their capacity to bind antibodies raised against the complete molecule in a direct binding assay. Results were compared to those obtained in a direct test using several peptide-BSA conjugates.