Merck, 10223565001, Histone

General description
Mixture of histones H1, H2A, H2B, H3, and H4, isolated from calf thymus.
Histones are a group of DNA-binding proteins that are characterized by relatively high levels of lysine and arginine. Five different fractions of histones have been isolated and characterized. These are named as H1, H2A, H2B, H3 and H4. The H1 fraction is lysine-rich, while the H2A and H2B are slightly lysine-rich, The H3 and H4 fractions are arginine-rich. The molecular weights of histones are approximately 11 to 21 kDa depending on the fraction.
Application
Histone from calf thymus has been used:
in in vitro kinase assay to check the phosphorylation of histones by protein kinase A.
to check the in vitro methyltransferase activity of protein argininemethyltransferases from Oryza sativa (OsPRMTs).
in anti-histone ELISA.

Biochem/physiol Actions
Histones have an important role in the organization and modification of chromatin. The nucleosome is the basic unit of the chromatin. It is made up of two molecules each of histones H2A, H2B, H3 and H4, wrapped with approximately 146bp of DNA. Histone H1 binds to the nucleosomes at the DNA entry and exit points and stabilizes them.
Physical form
Lyophilizate (natural mixture of histones H1, H2A, H2B, H3, and H4).
Preparation Note
Working concentration: 1 to 5 mg/ml.
Working solution: Recommended solvent is double-distilled water.
Storage conditions (working solution): Aqueous solution is stable at -15 to -25 °C for several months.
Avoid repeated freezing and thawing!
Other Notes
For life science research only. Not for use in diagnostic procedures.