A FRACTIONATION OF THE HISTONES OF GROUP F2A FROM CALF THYMUS.
Ontology highlight
ABSTRACT:
SUBMITTER: PHILLIPS DM
PROVIDER: S-EPMC1206417 | biostudies-other | 1965 Jan
REPOSITORIES: biostudies-other
Similar Datasets
Project description:1. Calf-thymus histones contain cysteine, which is present almost entirely in the arginine-rich fraction F3 to the extent of about 1mole in 15000g. weight of the histone. 2. The cysteine in fraction F3 is readily available to thiol reagents and the protein yields an approximately equivalent amount of cysteic acid on oxidation with performic acid.
| S-EPMC1264744 | biostudies-other
Project description:1. The same N-terminal peptide was isolated from two major calf thymus histone fractions, F2al and F2a2. 2. The structure of the peptides is N-acetylseryl-glycyl-arginine, and the yields account for most of the N-acetyl groups previously found in these histones. 3. Some other peptides not giving a ninhydrin reaction were also investigated.
| S-EPMC1198638 | biostudies-other
Project description:1. The lysine-rich fraction (Ia+Ib, or f1) of calf thymus histones was isolated as the sulphate by acid extraction. 2. Sedimentation-equilibrium measurements with interference optics showed that this fraction was monodisperse with a molecular weight of 19500+/-2000. 3. The ;apparent molecular weight' calculated from the sedimentation-equilibrium studies varied markedly with concentration. The large second virial coefficient implied by such variation was attributed to the very high charge/mass ratio of this relatively small protein. Estimates of the charge were made from the values of this virial coefficient. 4. The very large value of the virial coefficient explains anomalies in the earlier reports of the molecular weight of this histone and also why the z-average molecular weight can appear to be lower than the weight-average molecular weight. 5. The differences of the specific refractive increments, and the partial specific volumes, between dialysed and undialysed solutions of this histone fraction could also be attributed to its high molecular charge, which was estimated from these differences and agreed, within the expected limits, with the value deduced from the second virial coefficient. 6. Sedimentation-velocity measurements combined with the known molecular weight imply that lysine-rich histone has a high frictional ratio and an extended shape. Optical-rotatory-dispersion measurements indicated that it had a low helical content.
| S-EPMC1187204 | biostudies-other
Project description:Binding of adenosine(5')tetraphospho(5')adenosine (Ap4A) to histones of calf thymus was investigated by non-equilibrium dialysis. Histone H1 interacts with the dinucleotide via two strong sites and competes with Mg2+ ions. Intrinsic dissociation constants were 1.6 +/- 0.1 microM and 11 +/- 1 microM for zero and 0.4 mm-Mg2+ concentration respectively. Binding of poly(dT) and of other nucleotides to histone H1 was measured in an [3H]Ap4A-competition assay. The tendency to form complexes among nucleotides was highest for bisnucleoside tetraphosphates and decreased in the order poly(dT) greater than or equal to Ap4A approximately Gp4G greater than Ap4 much greater than Ap3A approximately Ap5A greater than or equal to ATP, GTP and dTTP. The co-ordination complex derived from Ap4A and cis-diammine-dichloroplatinum(II) was not reactive. The other histones of calf thymus also bound Ap4A with affinities decreasing in the order H4 approximately H3 greater than H1 greater than H2b greater than H2a. Ap4A stimulated the exchange of histone H1 between nucleosomes, but this effect was referred to ionic strength. It did not bind to assembled nucleosomes. Binding of Ap4A to histone H1 was decreased by salt (NaCl). At physiological saline concentration the value of the dissociation constant is commensurable with the value of the Ap4A concentration in the nucleus and thus indicative of complex-formation in vivo.
| S-EPMC1148332 | biostudies-other
Project description:Two-dimensional polyacrylamide-gel electrophoresis of acid extracts of thyroid and thymus tissue, and of thyroid nuclei, revealed the presence of three HClO4-soluble nuclear proteins, PS.1, PS.2 and PS.3, whose electrophoretic mobilities closely resembled those of HMG (high-mobility-group) proteins 14 and 17. PS.1 co-migrated with HMG 14 on CM-Sephadex column chromatography. Like HMG 14, PS.2 and PS.3 were phosphorylated in calf thyroid slices; 32P-labelling of PS.3 was stimulated by thyrotropin. Thyrotropin also induced a rapid increase in the labelling of A5, an HMG-14/17-like protein found in whole calf thyroid and thymus tissue, but not in thyroid nuclei.
| S-EPMC1152447 | biostudies-other
Project description:Studies of DNA molecule behavior in aqueous solutions performed through different approaches allow assessment of the solute-solvent interactions and examination of the strong influence of conformation on its physicochemical properties, in the presence of different ionic species and ionic concentrations. Firstly, the conformational behavior of calf-thymus DNA molecules in TE buffer solution is presented as a function of temperature. Secondly, their rheological behavior is discussed, as well as the evidence of the critical concentrations, i.e., the overlap and the entanglement concentrations (C* and Ce, respectively) from steady state flow and oscillatory dynamic shear experiments. The determination of the viscosity in the Newtonian plateau obtained from flow curves η ( ) allows estimation of the intrinsic viscosity and the specific viscosities at zero shear when C[η] < 40. At end, a generalized master curve is obtained from the variation of the specific viscosity as a function of the overlap parameter C[η]. The variation of the exponent s obtained from the power law η~ -s for both flow and dynamic results is discussed in terms of Graessley's analysis. In the semi-dilute regime with entanglements, a dynamic master curve is obtained as a function of DNA concentration (CDNA > 2.0 mg/mL) and temperature (10 °C < T < 40 °C).
| S-EPMC6432584 | biostudies-literature
Project description:1. Interactions of histone fractions with quinacrine mustard were investigated by fluorimetry and spectrophotometry and the results were interpreted with the aid of thinlayer chromatography. 2. Characteristic differences were found between the various histone fractions of calf thymus. The conditions that favoured histone conformational changes and aggregation, also favoured interaction between histones and the dye; low concentrations of SO(4) (2-) brought about more interaction than did Cl(-); urea, guanidinium and iodide ions were inhibitory to binding. 3. Changes in the physical state of all the quinacrine mustard-protein complexes occurred as a function of ionic strength and pH. The most salt-dependent interaction was found in the arginine-rich histone fraction. 4. The interaction of the calf thymus histone fractions with quinacrine mustard was compared with the interaction of bovine plasma albumin and protamine with quinacrine mustard. 5. The relationship between dye-binding and the aggregation of histone fractions was discussed.
| S-EPMC1177535 | biostudies-other
Project description:Molecular weights and sedimentation coefficients of four major fractions of calf thymus histones were measured. The minimum molecular weights were determined in concentrated solutions of guanidine hydrochloride. The results indicate that, with the possible exception of fraction F3, the fractions are heterogeneous. Comparisons in 0.1m-sodium chloride suggest that fraction F1 does not aggregate and show that fractions F2(a) and F3 aggregate to form larger complexes than does fraction F2(b). The degree of aggregation of each fraction is independent of pH in the range pH1-7. Detailed studies with fraction F2(b) have confirmed that the change in sedimentation coefficient observed as the sodium chloride concentration of the solution is increased results from increases in the apparent molecular weight of the sedimenting units. It has been found that the molecules of fraction F2(b) are present as single molecules only in sodium chloride solutions of 33mm or less. At these low concentrations the effects of charge greatly increase the concentration dependence of the sedimentation rate; the results can, however, be interpreted by using the theory developed by Alexandrowicz & Daniel (1963) and Daniel & Alexandrowicz (1963).
| S-EPMC1184847 | biostudies-other
Project description:1. The histones of Euglena gracilis were separated by gel filtration into five fractions. 2. Each fraction was characterized in terms of its electrophoretic, solubility and compositional properties. 3. Euglena gracilis clearly contains histones corresponding to vertebrate H1, H2B, H3 and H4 fractions, although they all differ in containing more lysine. 4. The remaining Euglena histone is considered to be homologous to vertebrate histone H2A, but it differs in having a much higher ratio of lysine to arginine. 5. The Euglena histone H1 appears to be lacking in aspartic acid. 6. Electrophoresis in the presence of sodium dodecyl sulphate indicates that the molecular weights of the Euglena histones are close to those of the homologous vertebrate histones.
| S-EPMC1184199 | biostudies-other
Project description:1. The incorporation of (14)C-labelled amino acids into acid-extractable proteins from rat-liver and -thymus nuclei confirmed the existence of a protein component with a higher uptake than that into the major histone components. 2. This rapidly labelled component appeared to contain the thiol groups detectable in the acid extracts. 3. Histone f1 contained 1mol. of serine phosphate/mol. of mol.wt. of 42000-43000. 4. Phosphate was present in other components of the 50mm-hydrochloric acid extract from liver and thymus nuclei, and was probably associated with the thiol-containing component. 5. The difference in amino acid uptake into the histones of diffuse and dense chromatin was confirmed. Dense chromatin was found to have a higher proportion of disulphide than did diffuse chromatin.
| S-EPMC1264933 | biostudies-other