Intrinsic fluorescence, difference spectrophotometry and theoretical studies on tertiary structure of calf thymus histone H1

The separation and purification of histone H1 from the sperm of the sea-urchin Sphaerechinus granularis is described. Physical studies were used to compare this histone H1 molecule with H1 histones from other species. C.d. and 270 MHz n.m.r. spectroscopy indicate that, despite significant compositional differences from other sea-urchin sperm H1 histones, their secondary and tertiary structures are very similar. A large difference in helicity was, however, found between S. granularis histone H1 and calf thymus histone H1, and their n.m.r. and fluorescence spectra also differ considerably. It is concluded that secondary structure and tertiary structure have not been conserved in the evolution of the H1 histone family.

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Secondary and tertiary structural differences between histone H1 molecules from calf thymus and sea-urchin (Sphaerechinus granularis) sperm

Biochemical Journal ◽

10.1042/bj1970655 ◽

1981 ◽

Vol 197 (3) ◽

pp. 655-660 ◽

Cited By ~ 22

Author(s):

V Giancotti ◽

E Russo ◽

S Cosimi ◽

P D Cary ◽

C Crane-Robinson

Keyword(s):

Structural Feature ◽

Sea Urchin ◽

Tertiary Structure ◽

Histone H1 ◽

Tryptic Digestion ◽

Chicken Erythrocyte ◽

Calf Thymus ◽

Helical Content ◽

Structural Differences ◽

Relationship Of

Tryptic digestion of histone H1 from the sperm of the sea urchin Sphaerechinus granularis leaves a limiting peptide of approx. 80 residues that is of similar size to the limit peptide from calf thymus H1 or chicken erythrocyte H5. The S. granularis limit peptide folds to form tertiary structure similar to that of the intact parent histone H1 (shown by n.m.r. spectra), but the helical content is decreased by the digestion from 64 residues to 28. In contrast, intact calf thymus H1 and chicken erythrocyte H5 histones have only about 28 helical residues, which are preserved in their limit peptides. The extra helix in S. granularis is shown to be rapidly digested away by trypsin, and its location in histone H1 is discussed. A possible relationship of this structural feature to the length of linker DNA is proposed.

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Precise elimination of the N-terminal domain of histone H1

Biochemical Journal ◽

10.1042/bj2030577 ◽

1982 ◽

Vol 203 (3) ◽

pp. 577-582 ◽

Cited By ~ 13

Author(s):

L Böhm ◽

P Sautière ◽

P D Cary ◽

C Crane-Robinson

Keyword(s):

Tertiary Structure ◽

Submaxillary Gland ◽

Spectroscopic Characterization ◽

Histone H1 ◽

Globular Domain ◽

Edman Degradation ◽

Terminal Domain ◽

C Terminus ◽

Mouse Submaxillary Gland ◽

Calf Thymus

The proteinase from mouse submaxillary gland was used to cleave total calf thymus histone H1 between residues 32 and 33. The C-terminal peptide, comprising residues 33 to the C-terminus, was purified and identified by amino acids analysis and Edman degradation. Spectroscopic characterization by n.m.r. for tertiary structure and by c.d. for secondary structure shows the globular domain of the parent histone H1 to be preserved intact in the peptide. It has therefore lost only the N-terminal domain and is a fragment of histone H1 comprising the globular plus C-terminal domains only. Precise elimination of only the N-terminal domain makes the fragment suitable for testing domain function in histone H1.

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Torus Circumference and Thickness Parameters From a Linear DNA Size Series Suggest How Toruses Self-Assemble

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119430 ◽

1985 ◽

Vol 43 ◽

pp. 522-523

Author(s):

George C. Ruben ◽

Kenneth A. Marx

Keyword(s):

Tertiary Structure ◽

Dna Complexes ◽

Tertiary Structures ◽

Self Assembling ◽

Double Stranded Dna ◽

Calf Thymus ◽

Dna Organization ◽

Condensed Dna ◽

Dna Size

Certain double stranded DNA bacteriophage and viruses are thought to have their DNA organized into large torus shaped structures. Morphologically, these poorly understood biological DNA tertiary structures resemble spermidine-condensed DNA complexes formed in vitro in the total absence of other macromolecules normally synthesized by the pathogens for the purpose of their own DNA packaging. Therefore, we have studied the tertiary structure of these self-assembling torus shaped spermidine- DNA complexes in a series of reports. Using freeze-etch, low Pt-C metal (10-15Å) replicas, we have visualized the microscopic DNA organization of both calf Thymus( CT) and linear 0X-174 RFII DNA toruses. In these structures DNA is circumferentially wound, continuously, around the torus into a semi-crystalline, hexagonal packed array of parallel DNA helix sections.

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p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.16.33 ◽

2020 ◽

Vol 16 ◽

pp. 337-350

Author(s):

Panagiotis S Gritzapis ◽

Panayiotis C Varras ◽

Nikolaos-Panagiotis Andreou ◽

Katerina R Katsani ◽

Konstantinos Dafnopoulos ◽

...

Keyword(s):

Energy State ◽

Theoretical Studies ◽

Triplet Energy ◽

Imine Group ◽

Sar Studies ◽

Double Stranded Dna ◽

Structure Activity ◽

Calf Thymus ◽

Carbamate Group ◽

Synthetic Nucleases

A number of p-pyridinyl oxime carbamate derivatives were prepared upon the reaction of the corresponding oximes with isocyanates. These novel compounds reacted photochemically in the presence of supercoiled plasmid DNA. Structure–activity relationship (SAR) studies revealed that the substituent on the imine group was not affecting the extend of the DNA damage, whereas the substituent of the carbamate group was critical, with the halogenated derivatives to be able to cause extensive single and double stranded DNA cleavages, acting as “synthetic nucleases”, independently of oxygen and pH. Calf thymus–DNA affinity studies showed a good-to-excellent affinity of selected both active and non-active derivatives. Preliminary theoretical studies were performed, in an effort to explain the reasons why some derivatives cause photocleavage and some others not, which were experimentally verified using triplet state activators and quenchers. These theoretical studies seem to allow the prediction of the activity of derivatives able to pass intersystem crossing to their triplet energy state and thus create radicals able to damage DNA. With this study, it is shown that oxime carbamate derivatives have the potential to act as novel effective photobase generating DNA-photocleavers, and are proposed as new leads for “on demand” biotechnological applications in drug discovery and medicine.

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Activity and conformational changes of horseradish peroxidase in trifluoroethanol

Biochemistry and Cell Biology ◽

10.1139/o02-003 ◽

2002 ◽

Vol 80 (2) ◽

pp. 205-213 ◽

Cited By ~ 6

Author(s):

Hong-Wei Zhou ◽

Yan Xu ◽

Hai-Meng Zhou

Keyword(s):

Enzyme Activity ◽

Horseradish Peroxidase ◽

Conformational Changes ◽

Tertiary Structure ◽

Polyacrylamide Gel Electrophoresis ◽

Intrinsic Fluorescence ◽

Two Phase ◽

Main Effect ◽

Α Helix ◽

Kinetics Of

The effect of trifluoroethanol (TFE) on horseradish peroxidase (HRP) was determined using activity assay and spectral analysis including optical absorption, circular dichroism (CD), and intrinsic fluorescence. The enzyme activity increased nearly twofold after incubation with 525% (v/v) concentrations of TFE. At these TFE concentrations, the tertiary structure of the protein changed little, while small changes occurred at the active site. Further increases in the TFE concentration (2540%) decreased the enzyme activity until at 40% TFE the enzyme was completely inactivated. The α-helix content of the protein increased at high TFE concentrations, while near-UV CD, Soret CD, and intrinsic fluorescence indicated that the tertiary structure was destroyed. Polyacrylamide gel electrophoresis results indicated that the surface charge of the enzyme was changed at TFE concentrations greater than 20%, and increasing concentrations of TFE reduced the enzyme molecular compactness. A scheme for the unfolding of HRP in TFE was suggested based on these results. The kinetics of absorption change at 403 nm in 40% TFE followed a two-phase course. Finally, HRP incubated with TFE was more sensitive to urea denaturation, which suggested that the main effect of TFE on HRP was the disruption of hydrophobic interactions.Key words: horseradish peroxidase, trifluoroethanol, unfolding, Soret.

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The binding of adenosine(5′)tetraphospho(5′)adenosine to calf thymus histones measured by non-equilibrium dialysis

Biochemical Journal ◽

10.1042/bj2460681 ◽

1987 ◽

Vol 246 (3) ◽

pp. 681-686 ◽

Cited By ~ 5

Author(s):

G Just ◽

E Holler

Keyword(s):

Ionic Strength ◽

Dissociation Constants ◽

Equilibrium Dialysis ◽

Physiological Saline ◽

Histone H1 ◽

The Other ◽

Competition Assay ◽

Calf Thymus ◽

Non Equilibrium

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.

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The selective extraction of histones from rye chromatin

Canadian Journal of Biochemistry ◽

10.1139/o76-109 ◽

1976 ◽

Vol 54 (9) ◽

pp. 765-771 ◽

Cited By ~ 7

Author(s):

Hélène LaRue ◽

Dominick Pallotta

Keyword(s):

Selective Extraction ◽

Histone H1 ◽

The Other ◽

Calf Thymus

The selective extraction of histones from rye chromatin was studied using three different methods. Extractions with NaCl–phosphate buffers atpH 5.5 gave results similar to those already obtained with other types of chromatin. Histone H1 was selectively extracted with 0.6 M NaCl –0.001 M PO4, while the selectivity of dissociation of the other fractions was reduced at higher NaCl concentrations. The use of phosphate–urea buffers at pH 5.5 also revealed that the histones were dissociated at the same concentrations as were calf thymus histones. Histone H1 was extracted with 0.5 M PO4 – 1 M urea; H1, H2A, and H2B were extracted with 0.8 M PO4 – 2 M urea; and all histones were removed with 0.8 M PO4 –5.3 M urea. It was, however, observed that the dissociated rye histones H2A and H2B were unstable in these buffers. This instability was maximum in the presence of 3 M urea, where both histones were absent from the extracted proteins and the residual nucleoproteins. Finally, a solution of 30% ethanol −0.35 M NaCl – 6 M urea produced a rye nucleoprotein fraction containing only histone H1.

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