The molecular weights and association of the histones of chicken erythrocytes

The Self‐Association of Chicken‐Erythrocyte Histones

“…Haydon and Peacocke [20] have shown that the second virial coefficient should be inversely proportional to the ionic strength and this is approximately so in this case (see inset, Fig.2). The values obtained for the molecular weight of histone F2c (H5) at infinite dilution in the range of solvents investigated are in good agreement with the values obtained in 6 M guanidinium chloride (see Table 1 and [6]). Greenaway [21] estimated the minimum molecular weight of the polypeptide chain as 18 400 by amino-acid analysis and after allowing for associated chloride ions this would increase to about 20 500.…”

“…As reported earlier [6] histone F2al (H4) from chicken erythrocytes associates much more strongly than do the other histones. Even in 0.4 M guanidinium chloride the sedimentation coefficient of histone F2al (H4) was 50 S; however, in 0.6 M guanidinium chloride unassociated monomers were formed.…”

“…The variation of the apparent molecular weights of the histone fractions with concentration, pH and ionic strength was first studied and has been published in summary already [6]. It was apparent that the analytical procedures of Adams [l] could be applied to such osmotic pressure and sedimentation results to obtain a measure of the stoichiometry and equilibrium constants of the observed association processes.…”

“…Isolated histones in solution tend to aggregate [4,5] and it is possible that this aggregation is a result of histone-histone interactions of the type normally responsible for maintaining correct chromosomal structure.We present here the results of an investigation of the factors influencing the aggregation of isolated histone fractions in solution. The variation of the apparent molecular weights of the histone fractions with concentration, pH and ionic strength was first studied and has been published in summary already [6]. It was apparent that the analytical procedures of Adams [l] could be applied to such osmotic pressure and sedimentation results to obtain a measure of the stoichiometry and equilibrium constants of the observed association processes.…”

Chance and Necessity in Arthur Peacocke's Scientific Work

“…Furthermore, Peacocke investigated the denaturation and renaturation of "naked" DNA and RNA (Cox, Jones, et al 1956;Lifson and Peacocke 1956;Thrower and Peacocke 1966;; he also extended these studies into the area of deoxyribonucleoproteins-combinations of DNA and protein isolated from cells as complex molecular assemblies and closer to the natural state of DNA in living cells than the pure DNA he studied in his prior work. Again, he investigated denaturation and renaturation under different conditions (Peacocke 1960;Bayley, Preston, et al 1962;Murray and Peacocke 1962;Lee, Walker, et al 1963;Lloyd and Peacocke 1965;Leveson and Peacocke 1966;Diggle and Peacocke 1968;Haydon and Peacocke 1968;Murray, Bradbury, et al 1970;Diggle, McVittie, et al 1975), and widened the spectra of possible causes of lesions resulting from exposure to gamma-ray irradiation (Peacocke and Preston 1961;Lloyd and Peacocke 1963;Lloyd, Nicholson, et al 1967) to ultrasound. Peacocke and his colleagues examined how ultrasound degrades DNA and other biomolecules (Pritchard, Hughes, et al 1966;Peacocke and Pritchard 1968a, b).…”