HISTONE TYPE VIII-S

Histone is suitable for use:

• as a positive control in the in vitro kinase assay to examine the ability of Cdc2-cyclin B1 to phosphorylate GST-CD-4 protein
• in Cdk5 activity assay
• in histone H1 kinase assay
• as a Poly(ADP-ribose) (PAR) acceptor in the assessment of in vitro PAR polymerase activity
• as an acceptor of ³²P from [γ-³²P]ATP in order to measure protein kinase activity of lysate from small and large luteal cells

Histones are octameric proteins containing H3, H4, H2A and H2B. It is the core protein around which DNA is wound forming the nucleosome structure. The core histone proteins contain globular domains. Each protein is composed of basic amino acids at its N-terminal. The H2A has an extra amino acid at its C-terminal end forming a histone tail. The nucleosome structure is stabilized by the linker histones during chromatin condensation.

Histones are a group of proteins characterized by high levels of lysine and arginine that form reversible complexes with DNA. Based on the fractions, the molar mass of histones varies between 11-21kDa. Five different fractions have been isolated and characterized. They include H1 (lysine rich), H2a and H2b that are slightly lysine rich, H3 and H4 that are arginine rich. H1 acts as a link between "beads" (nu bodies) on the chromatin chain.