On the fractionation of thymus histone

The N-terminal groups of calf-thymus histones

“…The average chain weight is about 25 000. This value and the nature of the chief end groups are, with the exception of alanine, at variance with the results of Haley (1955) and Luck et al (1956), which were obtained with histones prepared by extraction with sodium chloride and hydrochloric acid of thymuscell nuclei. In whole-thymus histones these authors found that valine accounted for 53 % of the Nterminal residues, leucine for 21 %, alanine for 18 % and glycine for 8 %.…”

“…Three samples of DNP-histones (H 1) have been hydrolysed under more vigorous conditions to liberate any valine which might be present as DNPvalyl-peptides (such as the DNP-valyl-e-DNPlysine reported by Luck et al 1956). Some valine peptides are notoriously stable to acid hydrolysis (Synge, 1945;Porter & Sanger, 1948).…”

“…It is difficult to account for these differences except on the assumption that degradation of the histones occurred in the preparative method used by Luck et al (1956). Although the histones are known to aggregate in alkaline solution , the reaction with 1-fluoro-2:4-dinitrobenzene is thought to have been complete since virtually no free lysine could be detected in the hydrolysates of DNP-histones.…”

“…It was expected that the results would be helpful in controlling the fractionation of the histones. While this work was in progress a dissertation on this topic appeared (Haley, 1955) and the work described has since been 3-2 published as part of a wider study of histones (Luck et al 1956). However, the results obtained here are not in good agreement with those reported.…”

Specificity of Silkgland Hl Histone

“…These remarkable antigenic differences in the H1 Histone of the silkgland and the calf thymus gland may mean that a great phylogenic divergency exists in this histone class. prepared from these pellets by the method of Johns (8), followed by ion-exchange column chromatography of Amberlite CG-50 with guanidine hydrochloride (9). The histones were purified by a semi-preparative polyacrylamide gel electrophoresis as described by Panyim and Chalkley (10).…”