Composition of Histone prepared from Rat Liver Deoxypentosenucleoprotein

Abstract

THE recent report¹ by Hamer on the amino-acid composition of calf thymus histone prompts us to communicate some corresponding observations on a histone prepared from rat liver deoxypentosenucleoprotein. Nuclei were isolated from briefly homogenized suspensions of perfused rat liver (Sprague–Dawley–Holtzmann strain) and washed four times. A citric acid technique at pH 6.1 was employed in the preparation². The nuclei were subjected to differential extraction with sodium chloride, 1.0 M salt being used for the extraction of the deoxypentosenucleoprotein and dilution to 0.14 M salt for its precipitation. Unlike the preparations described in the literature, these are non-fibrous on precipitation, readily soluble in water, non-viscous in either water or molar sodium chloride solution, and of low molecular weight. The deoxypentosenucleoprotein was dialysed against water and the solution so obtained was lyophilized.