THE BINDING OF ANIONS BY LYSOZYME, CALF THYMUS HISTONE SULPHATE, AND PROTAMINE SULPHATE

1952 ◽  
Vol 30 (4) ◽  
pp. 320-331 ◽  
Author(s):  
J. Ross Colvin
Keyword(s):  
Protein Binding ◽  
Temperature Coefficient ◽  
Adsorption Isotherms ◽  
Large Series ◽  
Orange Ii ◽  
General Process ◽  
Protamine Sulphate ◽  
Calf Thymus ◽  
Pass Through ◽  
Positively Charged

The adsorption of a large series of anions by positively charged lysozyme, calf thymus histone sulphate, and protamine sulphate has been studied by dialysis equilibrium. One group of anions was not adsorbed by lysozyme while the adsorption isotherms for Orange I, Orange II, and 2, 4-dinitro-1-naphthol-7-sulphonic acid were S-shaped. These anomalous isotherms, which were also obtained with histone sulphate and protamine sulphate, have an appreciable temperature coefficient at intermediate dye concentrations. It is emphasized that this type of adsorption is inconsistent with the exclusively electrostatic view of protein binding of anions. It is also shown that −ΔF, −ΔH, and ΔS per mole of anion bound must pass through a maximum for intermediate free anion concentrations in such systems. The lack of binding of some anions and the anomalous isotherms for others is interpreted in terms of a solvation sheath about the charged protein. Their significance for the general process of binding of ions by proteins is discussed.

Conformations of calf thymus and rye histones H3 and H4 in aqueous solution by laser Raman spectroscopy

1980 ◽  
Vol 58 (8) ◽  
pp. 633-640 ◽  
Author(s):  
M. Pézolet ◽  
R. Savoie ◽  
J.-G. Guillot ◽  
M. Pigeon-Gosselin ◽  
D. Pallotta
Keyword(s):  
Laser Raman Spectroscopy ◽  
Carboxylate Group ◽  
Weakly Bound ◽  
Tyrosine Residues ◽  
Laser Raman ◽  
Calf Thymus ◽  
Sheet Structure ◽  
High Degree ◽  
Β Sheet ◽  
Positively Charged

The Raman spectra of aqueous solutions of histones H3 and H4 from calf thymus and from rye reflect the high degree of conservation from species to species of the primary and secondary structures of these proteins. The amount of β-sheet structure is estimated at 40 ± 5% in H4 and at 33 ± 5% in H3 from the intensities of the amide I and amide III bands at 1663 and 1241 cm−1, respectively, in the spectra. These values are independent of the salt concentration of the solutions, most likely because of the high histone concentration (~3 mM) required to obtain the spectra, which results in some aggregation of the proteins. The intensity ratio of the tyrosine doublet at 852 and 826 cm−1 indicates that the four tyrosine residues in H4 are relatively exposed to the solvent or weakly bound to positively charged groups of basic amino acids, whereas in H3 at least one tyrosine is buried inside the protein and tightly bound to a carboxylate group. The results also show that the secondary structure of H3 is slightly influenced by the state of oxidation of the two cysteine residues it contains.

scholarly journals Structural basis for substrate specificity of an amino acid ABC transporter

2015 ◽  
Vol 112 (16) ◽  
pp. 5243-5248 ◽  
Author(s):  
Jie Yu ◽  
Jingpeng Ge ◽  
Johanna Heuveling ◽  
Erwin Schneider ◽  
Maojun Yang
Keyword(s):  
Amino Acid ◽  
Abc Transporters ◽  
Transmembrane Domain ◽  
Structural Basis ◽  
Common Mechanism ◽  
Nucleotide Binding Domain ◽  
Functional Studies ◽  
Thermoanaerobacter Tengcongensis ◽  
Pass Through ◽  
Positively Charged

ATP-binding cassette (ABC) transporters are ubiquitous integral membrane proteins that translocate a variety of substrates, ranging from ions to macromolecules, either out of or into the cytosol (hence defined as importers or exporters, respectively). It has been demonstrated that ABC exporters and importers function through a common mechanism involving conformational switches between inward-facing and outward-facing states; however, the mechanism underlying their functions, particularly substrate recognition, remains elusive. Here we report the structures of an amino acid ABC importer Art(QN)2 from Thermoanaerobacter tengcongensis composed of homodimers each of the transmembrane domain ArtQ and the nucleotide-binding domain ArtN, either in its apo form or in complex with substrates (Arg, His) and/or ATPs. The structures reveal that the straddling of the TMDs around the twofold axis forms a substrate translocation pathway across the membrane. Interestingly, each TMD has a negatively charged pocket that together create a negatively charged internal tunnel allowing amino acids carrying positively charged groups to pass through. Our structural and functional studies provide a better understanding of how ABC transporters select and translocate their substrates.

scholarly journals The properties of a nuclear acidic protein fraction that binds [6,7−3H]oestradiol-17β

1969 ◽  
Vol 114 (3) ◽  
pp. 649-657 ◽  
Author(s):  
R. J. B. King ◽  
J. Gordon ◽  
A W Steggles
Keyword(s):  
Common Property ◽  
Polyacrylamide Gel Electrophoresis ◽  
Convincing Evidence ◽  
Acidic Protein ◽  
Mammary Adenocarcinoma ◽  
Receptor Protein ◽  
Unit Weight ◽  
Partial Purification ◽  
Protamine Sulphate ◽  
Calf Thymus

1. Additional evidence was obtained that the nuclear oestradiol-17β receptor is an acidic protein. Partial purification of the receptor protein was obtained by chromatography on hydroxyapatite and it contains protein-bound phosphate. 2. The nuclear ‘5s’ and cytoplasmic ‘9·5s’ and ‘5s’ receptors from uterus, dimethylbenzanthracene-induced mammary adenocarcinoma and kidney are precipitated together with bound oestradiol-17β by protamine sulphate. This common property suggests that the nuclear and cytoplasmic receptors are related to each other. 3. The properties of two acidic protein fractions from both liver and dimethylbenzanthracene-induced mammary adenocarcinoma are described. Fraction 1 contains two major components and fraction 2 contains one component, as judged from polyacrylamide-gel electrophoresis. Fraction 2 contains RNA and both fractions contain protein-bound phosphate. 4. These fractions form insoluble complexes with calf thymus histone, protamine sulphate and poly-l-lysine. The formation of these complexes is markedly affected by ionic strength and pH. Ionization of both the ∈-amino group of lysine and carboxyl group are involved. RNA and DNA do not appear to be involved. The interaction is not affected by EDTA or 1mm-Na+, -K+, -Ca2+, -Mg2+ or -Mn2+. Per unit weight, whole histone has 4–5 times as many binding sites for the acidic proteins as the latter have for the former. 5. No convincing evidence was obtained for DNA–acidic protein interaction, but, as judged from precipitation experiments, there was competition between DNA and acidic protein for histone. 6. Relatively large amounts of acidic protein partly relieved the histone inhibition of the template activity of DNA for Escherichia coli RNA polymerase (EC 2.7.7.6).

ADSORPTION OF ORANGE II BY CYTOCHROME c AND RIBONUCLEASE

1954 ◽  
Vol 32 (3) ◽  
pp. 184-188 ◽  
Author(s):  
J. Ross Colvin
Keyword(s):  
Methyl Orange ◽  
Cytochrome C ◽  
Adsorption Isotherms ◽  
Acetate Buffer ◽  
Orange Ii

The adsorption isotherms of Orange II on cytochrome c and ribonuclease at pH 5.5 in 0.05 M acetate buffer are sigmoid. They may be interpreted by a previously described theory of interacting hydration effects. Adsorption of methyl orange or sodium flavianate by either protein was negligible.

scholarly journals Adsorptive Removal of Anionic Azo Dye New Coccine Using Silica and Silica-gel with Surface Modification by Polycation

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1536
Author(s):  
Tien Duc Pham ◽  
Viet Phuong Bui ◽  
Thuy Nga Pham ◽  
Thi Mai Dung Le ◽  
Kim Thuy Nguyen ◽  
...  
Keyword(s):  
Silica Gel ◽  
Adsorption Isotherms ◽  
Azo Dye ◽  
Dye Adsorption ◽  
Surface Group ◽  
Modified Silica ◽  
Modified Silica Gel ◽  
As Adsorption ◽  
Langmuir And Freundlich Models ◽  
Positively Charged

In the present work, adsorption of anionic azo dye, new coccine (NCC) on silica and silica-gel in an aquatic environment was discovered. Effective conditions such as adsorption time, pH, the influence of dosage on NCC adsorption using strong polycation, poly-diallyl-dimethylammonium chloride (PDADMAC) modified silica (PMS) and PDADMAC modified silica-gel (PMSG) were systematically studied. The removal of NCC using PMS and PMSG were much higher than that using raw silica and silica-gel without PDADMAC in all pH ranges from 3 to 10. The adsorption of NCC onto PMS and PMSG was achieved maxima at the same conditions of contact time 30 min, pH 6. The optimum adsorbent dosages of PMS and PMSG for NCC removal were 10 and 20 mg·mL−1, respectively. Experimental results of NCC adsorption isotherms onto PMS and PMSG at different ionic strength were fitted by Langmuir and Freundlich models. The NCC removal efficiencies using PMS and PMSG were higher than 87%, indicating that PMS and PMSG are novel and reusable adsorbents for removal of anionic dye. Based on adsorption isotherms, and surface group changes after PDADMAC modification and NCC adsorption examined by Fourier transform infrared spectroscopy (FTIR), we demonstrate that electrostatic interaction between positively charged adsorbents’ surfaces and negative sulfonic groups of NCC are the main driving force for anionic azo dye adsorption onto PMS and PMGS adsorbents.

ADSORPTION OF ORANGE II BY CYTOCHROME c AND RIBONUCLEASE

1954 ◽  
Vol 32 (1) ◽  
pp. 184-188
Author(s):  
J. Ross Colvin
Keyword(s):  
Methyl Orange ◽  
Cytochrome C ◽  
Adsorption Isotherms ◽  
Acetate Buffer ◽  
Orange Ii

The adsorption isotherms of Orange II on cytochrome c and ribonuclease at pH 5.5 in 0.05 M acetate buffer are sigmoid. They may be interpreted by a previously described theory of interacting hydration effects. Adsorption of methyl orange or sodium flavianate by either protein was negligible.

scholarly journals THE INTERNAL ADSORPTION ISOTHERMS IN THE DYEING OF VINYLON WITH ORANGE II

1962 ◽  
Vol 18 (8) ◽  
pp. 736-740
Author(s):  
Akira Katayama ◽  
Nobuhiko Kuroki ◽  
Kenzo Konishi
Keyword(s):  
Adsorption Isotherms ◽  
Orange Ii ◽  
Internal Adsorption

scholarly journals Can an Intermediate Rate of Nitrogen Inversion Affect Drug Efficacy?

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1753
Author(s):  
Raphael R. Steimbach ◽  
Gergely Tihanyi ◽  
Magalie N. E. Géraldy ◽  
Alicja Wzorek ◽  
Aubry K. Miller ◽  
...  
Keyword(s):  
Protein Binding ◽  
Drug Efficacy ◽  
Intermediate Range ◽  
Nitrogen Inversion ◽  
In Silico Drug Design ◽  
Pass Through ◽  
The Times ◽  
And Diffusion ◽  
Intermediate Rate

Nitrogen-inversion rates and diffusion coefficients were measured using 1H NMR for 14 drug-like molecules. The slow nitrogen-inversion rates interconverting the enantiomers of these molecules lay within a postulated intermediate range in terms of their ability to bind to proteins bounded by diffusion constraints, potentially affecting the availability, hence efficacy, of these compounds if they were utilized as drugs. The postulated intermediate range is based on a capture-volume concept, whereby the nitrogen inversion during the time a ligand takes to pass through a volume surrounding the protein binding site, as calculated by the diffusion rate, determines if it will influence ligand binding to the protein. In the systems examined here, the measured nitrogen-inversion rates and the times required to traverse the capture volume differed by a few orders of magnitude. Potentially more consequential are intermediate nitrogen-inversion rates in epimeric cases—since the energies of the interconverting species are unequal, a heavy bias against the eutomer might occur. The implications of an intermediate nitrogen-inversion rate are significant for in silico drug design, drug efficacy, molecular modeling of drug–protein binding, pharmacokinetics, drug enantiomer evaluation, etc. Due consideration of the process should thus be taken into account for drug development directions and in vitro evaluation.

Sign in / Sign up

Export Citation Format

Share Document