Merck, H5505-25MG, Histone from calf thymus

Application
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

Biochem/physiol Actions
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.
Features and Benefits
Do not confuse Sigma "Type" designations with the "Fraction" designations used by Luck and co-workers.
Preparation Note
Lysine-rich fraction as isolated and described by de Nooij, E. and Westenbrink, H.G., Biochim. Biophys. Acta, 62, 608 (1962).
Other Notes
Characterized as mainly subgroup f₁ by SDS-PAGE