scholarly journals Hyaluronan-Arginine Interactions—An Ultrasound and ITC Study

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2069
Author(s):  
Adam Jugl ◽  
Miloslav Pekař
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
High Resolution ◽  
Isothermal Titration Calorimetry ◽  
High Ionic Strength ◽  
Point Of View ◽  
Random Coil ◽  
Titration Calorimetry

High-resolution ultrasound spectroscopy and isothermal titration calorimetry were used to characterize interactions between hyaluronan and arginine oligomers. The molecular weight of arginine oligomer plays an important role in interactions with hyaluronan. Interactions were observable for arginine oligomers with eight monomer units and longer chains. The effect of the ionic strength and molecular weight of hyaluronan on interactions was tested. In an environment with increased ionic strength, the length of the arginine oligomer was crucial. Generally, sufficiently high ionic strength suppresses interactions between hyaluronan and arginine oligomers, which demonstrated interactions in water. From the point of view of the molecular weight of hyaluronan, the transition between the rod conformation and the random coil conformation appeared to be important.

scholarly journals Nucleic acid enzymology of extremely halophilic bacteria. Halobacterium cutirubrum polynucleotide phosphorylase

1971 ◽  
Vol 121 (4) ◽  
pp. 613-620 ◽  
Author(s):  
Pearl I. Peterkin ◽  
P. S. Fitt
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Nucleic Acid ◽  
Halophilic Bacteria ◽  
High Ionic Strength ◽  
Low Molecular Weight ◽  
Polynucleotide Phosphorylase

1. Polynucleotide phosphorylase was purified 200-fold from Halobacterium cutirubrum. 2. It is membrane-associated and can be solubilized by sonication. 3. The purified enzyme requires a high ionic strength for both stability and activity. 4. It is Mn2+-dependent, has all three typical polynucleotide phosphorylase activities and is specific for nucleoside diphosphates. 5. The enzyme is of low molecular weight.

Breakdown and reassociation of bacterial spinae

1982 ◽  
Vol 28 (7) ◽  
pp. 795-808
Author(s):  
K. B. Easterbrook ◽  
R. W. Coombs
Keyword(s):  
Ionic Strength ◽  
Protein Conformation ◽  
High Ionic Strength ◽  
Random Coil ◽  
Temperature Dependent ◽  
Calcium Effect ◽  
Α Helix ◽  
Low Ionic Strength ◽  
Β Sheet ◽  
Polymeric Structures

The tubular appendage, spina (Easterbrook and Coombs. 1976. Can. J. Microbiol. 22: 438–440), dissociates most efficiently under conditions of low ionic strength (0.01 M), high pH (10), and high temperature (95 °C). The protomer, spinin, thus produced is stable under these conditions and reassociates on cooling to give two distinct filamentous polymeric structures that differ in their stability, protein conformation, and reassociation characteristics. Under conditions of low ionic strength (0.01 M), reassociation is relatively slow and leads to a product that has significant amounts of α-helix in addition to the high β-sheet component; under conditions of high ionic strength (1 M), reassociation is rapid and the non-β-sheet component is in the random coil configuration. Since polymerization of the latter structure is "seeded" by either endogenous or exogenously supplied spina fragments, the protomers comprising it are assumed to be in the same conformation as in the spinae. High ionic strength induces folding of the protomer, multimeric association, and finally, elongation by a temperature-dependent process. Reassociation appears to be pH (6–10) independent and, apart from a possible minor calcium effect, cation nonspecific.

Dissociation of Factor VIII in the Presence of Proteolytic Inhibitors

1978 ◽  
Vol 40 (02) ◽  
pp. 316-325 ◽  
Author(s):  
Ira I Sussman ◽  
Harvey J Weiss
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Factor Viii ◽  
Direct Evidence ◽  
Gel Filtration ◽  
High Ionic Strength ◽  
Procoagulant Activity ◽  
Low Molecular Weight ◽  
Bean Trypsin Inhibitor ◽  
Benzamidine Hydrochloride

SummaryWhen gel filtration of factor VIII is performed with buffers of high ionic strength (1.0 M NaCl or 0.25 M CaCl2), the procoagulant activity elutes with proteins of relatively low molecular weight. It has been suggested that in the presence of proteolytic inhibitors, the procoagulant activity would appear at the void volume. To test this hypothesis, chromatography with buffers of high ionic strength was performed in the presence of benzamidine hydrochloride, soy bean trypsin inhibitor, heparin, DFP, and aprotinin. Under all of these conditions, the procoagulant activity continued to elute with proteins of low molecular weight. Similar findings were obtained after chromatographing cryoprecipitate prepared from the plasma of a normal subject who had received heparin. Thus, at present there is no direct evidence to suggest that proteolysis is involved in the dissociation of factor VIII by buffers of high ionic strength.

scholarly journals A comparison of methods for extracting ribonucleic acid polymerases from rat liver nuclei

1979 ◽  
Vol 183 (1) ◽  
pp. 43-54 ◽  
Author(s):  
T J C Beebee
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Rna Polymerase Ii ◽  
Rat Liver ◽  
High Ionic Strength ◽  
Rna Polymerases ◽  
Comparison Of Methods ◽  
Optimal Conditions ◽  
Liver Nuclei ◽  
Enzyme Molecules

Nuclei were prepared from rat liver after homogenization of the tissue in hyperosmotic sucrose and RNA polymerases (EC 2.7.7.6) extracted by two methods applied sequentially. Optimal conditions for washing loosely bound enzymes out of nuclei were determined first, and involved short (10 min) incubations at 0 degrees C in the presence of 5 mM-Mg2+ and 60 mM-(NH4)2SO4. Subsequent sonication of the residual nuclear pellet after resuspension and lysis at high ionic strength resulted in further release of RNA polymerases. The primary wash yielded about 2 × 10(4) molecules of RNA polymerases I and III (altogether) and 1 × 10(4) molecules of form-II enzymes per original nucleus, whereas subsequent sonication released 2 × 10(4)-2.5 × 10(4) form-I and -III enzyme molecules (altogether) and a further 7 × 10(3)-8 × 10(3) form-II enzyme molecules, as measured by end-labelling of nascent RNA. RNA polymerase II was partially purified from both types of extracts and shown to initiate very poorly on high-molecular-weight homologous DNA irrespective of the source of the enzyme.

Interactions between Oppositely Charged Polyelectrolytes by Isothermal Titration Calorimetry: Effect of Ionic Strength and Charge Density

2017 ◽  
Vol 121 (12) ◽  
pp. 2684-2694 ◽  
Author(s):  
Feriel Meriem Lounis ◽  
Joseph Chamieh ◽  
Laurent Leclercq ◽  
Philippe Gonzalez ◽  
Amine Geneste ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Charge Density ◽  
Isothermal Titration Calorimetry ◽  
Titration Calorimetry ◽  
Oppositely Charged

scholarly journals Purification and Some Properties of Tissue Plasminogen Activator

1977 ◽  
Author(s):  
P. Wallén ◽  
M. Rånby
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Specific Activity ◽  
Chemical Properties ◽  
Potassium Thiocyanate ◽  
Test System ◽  
Point Of View ◽  
Physiological Importance ◽  
Functional Point ◽  
Study Sites

A highly purified preparation of plasminogen tissue activator from pig heart has been prepared for studies on its chemical properties and on its interaction with fibrin and fibrinogen from the functional point of view. Essential steps in the purification procedure are two affinity adsorbtions involving two different sites in the activator molecule. 1. Affinity adsorbtion to fibrin followed by elution in two steps with potassium thiocyanate and phenylethylamine. 2. Affinity chromatography on Sepharose-arginine. The final product moves as a single band on SDS-polyacrylamidegel electrophoresis although an additional trace component is sometimes observed. The specific activity is at least 150 000 CTA units//mg protein as measured in a fibrinolytic test system. The molecular weight measured by SDS-polyacrylamidegel electrophoresis is 63 000 dalton before reduction. Reduced samples still appear as one fraction on electrophoresis, but the molecular weight has diminished to about 31 000 dalton, i. e. half the original value. The highly purified activator is labile in neutral solutions of low ionic strength but is stabilized by increasing the ionic strength to 1. The firm and specific adsorbtion of tissue activator to fibrin is presumably of physiological importance. Attempts are therefore made to study sites in fibrin (fibrinogen) with affinity for tissue activator. Preliminary experiments indicate that one site is situated in the part of Aα chain which is released from fibrinogen or fibrin early during digestion with plasmin.

scholarly journals Preparation and properties of amphipathic enzyme-polymer conjugates

1979 ◽  
Vol 181 (1) ◽  
pp. 111-118 ◽  
Author(s):  
R A G Smith
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Ionic Strength ◽  
High Molecular Weight ◽  
Immiscible Liquid ◽  
High Ionic Strength ◽  
Polymer Conjugates ◽  
Ionic Detergents ◽  
Oil In Water

Amphipathic enzyme-polymer conjugates were prepared by reaction of hydrophilic enzymes with an anhydride polymer partially substituted with pendant hydrophobic groups. The products formed non-covalent aggregates of high molecular weight, dissociable by non-ionic detergents and urea and subject to additional aggregation at high ionic strength. Oil-in-water emulsions formed in the presence of such conjugates were shown to possess enzyme activity associated with the surface of the water-immiscible liquid. Fluorochrome labelling of conjugates showed that binding occurred at the surface of solvent droplets, and the conjugates were also found to aggregate liposomes.

Sign in / Sign up

Export Citation Format

Share Document