Description_x000D_ Application_x000D_ Histone is suitable for use:_x000D_ • as a positive control in the in vitro kinase assay to examine the ability of Cdc2-cyclin B1 to phosphorylate GST-CD-4 protein_x000D_ • in Cdk5 activity assay_x000D_ • in histone H1 kinase assay_x000D_ • as a Poly(ADP-ribose) (PAR) acceptor in the assessment of in vitro PAR polymerase activity_x000D_ • as an acceptor of 32P from [γ-32P]ATP in order to measure protein kinase activity of lysate from small and large luteal cells_x000D_ Packaging_x000D_ 25, 100, 250 mg in poly bottle_x000D_ Biochem/physiol Actions_x000D_ 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._x000D_ Features and Benefits_x000D_ Do not confuse Sigma "Type" designations with the "Fraction" designations used by Luck and co-workers._x000D_ Other Notes_x000D_ Characterized as mainly subgroup f1 by SDS-PAGE_x000D_ Preparation Note_x000D_ Lysine-rich fraction as isolated and described by de Nooij, E. and Westenbrink, H.G., Biochim. Biophys. Acta, 62, 608 (1962).