Antithrombin I Activity

1959 ◽  
Vol 03 (04) ◽  
pp. 640-653 ◽  
Author(s):  
Marc Verstraete ◽  
Carl Vermylen
Keyword(s):  
Ionic Strength ◽  
Side Effect ◽  
Thrombin Inhibitor ◽  
Plasma Samples ◽  
Thrombin Inhibition ◽  
Antithrombin Activity ◽  
Congenital Afibrinogenemia ◽  
High Concentrations ◽  
Low Ionic Strength ◽  
High Degree

Summary1. Our experiments demonstrate that antithrombin I interferes considerably in the thrombin inhibitor determination described by Jürgens. A similar interference can be suspected in the immediate antithrombin determinations as described by other investigators in experiments based on the same principle.2. The thrombin-adsorbing capacity of fibrin depends to a high degree on the ionic strength of the medium: low ionic strength enhances, while high concentrations inhibite antithrombin J activity.3. After allowing for antithrombin I interference in the total thrombin inhibition, there was still measurable direct antithrombin activity present. The magnitude of the latter is directly correlated to the antithrombin capacity found in plasma samples free of the antithrombin I side-effect. Such plasma samples were obtained from a patient with congenital afibrinogenemia and heat-defibrinated normal plasma.

A Simple Method to Measure Dermatan Sulfate at Sub-Microgram Concentrations in Plasma

1988 ◽  
Vol 60 (02) ◽  
pp. 236-239 ◽  
Author(s):  
D Dupouy ◽  
P Sié ◽  
F Dol ◽  
B Boneu
Keyword(s):  
Ionic Strength ◽  
Dermatan Sulfate ◽  
Ex Vivo ◽  
Thrombin Inhibitor ◽  
Heparin Cofactor Ii ◽  
Simple Method ◽  
Thrombin Inhibition ◽  
Thrombin Activity ◽  
Short Period ◽  
Low Ionic Strength

SummaryA simple method for biological assay of dermatan sulfate (DS) in plasma is described. DS accelerates thrombin inhibition by heparin cofactor II (HC II). The principle of the assay is to measure the residual amidolytic thrombin activity after a short period of incubation with HC II in defibrinated plasma at low ionic strength. For this method we take advantage of two observations. Firstly, at fixed concentrations of DS and of HC II, the rate of thrombin inhibition increases when the ionic strength of the medium decreases. Secondly, defibrination by bentonite absorption also removes antithrombin III, HC II and for a large part alpha-2 macroglobulin from the plasma, so that no other thrombin inhibitor competes with HC II added as a reagent in a second step.In the conditions described, there is a linear relationship between DS concentrations in plasma from 0 to 2 μg/ml and the log of residual thrombin activity. The limit of sensitivity is 0.1 μg/ ml. The assay displays an acceptable reproducibility in intraassay, inter-assay and inter-individual experiments. It can be used to measure DS in human, rabbit and rat plasmas. The assay is also sensitive to other HC II activators such as heparin and pentosan polysulfate.DS is effective in experimental thrombosis without any detectable anticoagulant effect ex vivo. Pharmacological concentrations of DS in plasma fall into the range of sensitivity of this assay, which would be helpful in experimental or clinical studies of DS and related glycosaminoglycans.

scholarly journals A novel procedure for the rapid purification of plastocyanin from pea (Pisum sativum) leaves

1981 ◽  
Vol 193 (1) ◽  
pp. 375-378 ◽  
Author(s):  
A R Ashton ◽  
L E Anderson
Keyword(s):  
Ionic Strength ◽  
Pisum Sativum ◽  
Deae Cellulose ◽  
High Concentrations ◽  
Rapid Purification ◽  
Low Ionic Strength

Plastocyanin is soluble at high concentrations (greater than 3 M) of (NH4)2SO4 but under these conditions will adsorb tightly to unsubstituted Sepharose beads. This observation was utilized to purify plastocyanin from pea (Pisum sativum) in two chromatographic steps. Sepharose-bound plastocyanin was eluted with low-ionic-strength buffer and subsequently purified to homogeneity by DEAE-cellulose chromatography.

scholarly journals The Impact of Universal Transport Media and Viral Transport Media Liquid Samples on a SARS-CoV-2 Rapid Antigen Test

2021 ◽  
Author(s):  
Jeff Mayfield ◽  
Peter Hesse ◽  
David Ledden
Keyword(s):  
Ionic Strength ◽  
False Positive ◽  
Antigen Test ◽  
Liquid Samples ◽  
Viral Transport ◽  
Extraction Buffer ◽  
High Concentrations ◽  
Low Ionic Strength ◽  
The Impact ◽  
Positive Results

The impact of universal transport media (UTM) and viral transport media (VTM) liquid samples on the performance of the Healgen Scientific Rapid COVID-19 Antigen Test was investigated. Twelve different UTM/VTM liquid samples were added at different dilutions to the extraction buffer, and 2 of 12 generated false-positive results. To understand the cause of these false-positive results, the effect of extraction buffer dilution on sample pH, surfactant concentration, and ionic strength were investigated. The most important factor in UTM/VTM liquid sample dilution of the extraction buffer was ionic strength as measured by conductivity. Dilutions with conductivity below ~17 mS/cm can induce a false-positive result. It was also noted that the ionic strength of UTM/VTMs can vary, and those with low ionic strength can be problematic. To rule out the effect of other common components found in UTMs/VTMs, several materials were mixed with extraction buffer and tested at high concentrations. None was shown to produce false-positive results.

Isolation of Antithrombin Globulin from Human Blood Plasma

1960 ◽  
Vol 4 (01) ◽  
pp. 017-030
Author(s):  
George Y. Shinowara ◽  
Dimite J. Buckley
Keyword(s):  
Ionic Strength ◽  
Test Procedure ◽  
Human Blood Plasma ◽  
First Order ◽  
Antithrombin Activity ◽  
Low Concentrations ◽  
Fractionation Procedure ◽  
The Mean ◽  
Low Ionic Strength ◽  
Kinetics Of

SummaryFraction III + IV obtained by a low temperature — low ionic strength fractionation procedure was found to contain 97 percent of the antithrombin activity of whole plasma. The mean antithrombin activity in this fraction from 88 normal plasma specimens was 172.6 ± S. D. 19.8 units per ml. Further purification experiments resulted in fraction III representing 96 per cent of the antithrombin activity in fraction III + IV. There was no evidence for fibrinogen, prothrombin and antihemophilic globulin contamination in fraction III. Over 90 per cent of the plasma gamma globulins was present in this fraction.The kinetics of the thrombin-antithrombin reaction were investigated. Under the specific conditions employed, the reaction was found to follow a first order course. The heat of activation was determined to be 11,300 calories. A standard antithrombin unit is defined. A quantitative test procedure which is accurate at both high and low concentrations of the circulating anticoagulant is described and its application on fractions, heat defibrinated plasma and serum is discussed.

7-Diethylamino-3-((4′-iodoacetylamino)phenyl)-4-methylcoumarin, a fluorescent probe of the hydrophobic cleft in the tropomyosin coiled coil

1988 ◽  
Vol 66 (8) ◽  
pp. 1805-1808 ◽  
Author(s):  
Leslie D. Burtnick ◽  
Anita Racic
Keyword(s):  
Ionic Strength ◽  
Skeletal Muscles ◽  
Coiled Coil ◽  
Cysteine Residue ◽  
Deoxyribonuclease I ◽  
Low Ionic Strength ◽  
Hydrophobic Cleft ◽  
Polypeptide Chains ◽  
High Degree ◽  
Rabbit Skeletal Muscles

A sulfhydryl-specific fluorescent reagent, 7-diethylamino-3-((4′-iodoacetylamino)phenyl)-4-methylcoumarin (DCIA) was used to label cysteine residues on tropomyosin (TM) from rabbit cardiac and rabbit skeletal muscles. The emission maximum at 486 nm, the high degree of fluorescence polarization, and the limited accessibility of the bound probe to quenching by iodide suggest that the probe is bound in the hydrophobic cleft between polypeptide chains of the TM coiled coil, as well as being bound covalently at a cysteine residue. The labelled TMs retain their abilities to bind F-actin and are able to interact with deoxyribonuclease I. They, however, show a reduced tendency to aggregate into filaments in low ionic strength solutions.

The Modification of Actomyosin ATPase Activity by Tropomyosin-Troponin and its Dependence on Ionic Strength, ATP-Concentration, and Actin-Myosin Ratio

1974 ◽  
Vol 29 (9-10) ◽  
pp. 496-505 ◽  
Author(s):  
Peter Daneker
Keyword(s):  
Ionic Strength ◽  
Atpase Activity ◽  
Actin Filaments ◽  
Regulatory Proteins ◽  
High Affinity ◽  
Low Concentrations ◽  
Dependence On Ionic Strength ◽  
High Concentrations ◽  
Low Ionic Strength ◽  
Better Than

Abstract At millimolar concentrations of ATP the ATPase activity of regulated actomyosin (which consisted of myosin and of actin containing the regulatory proteins tropomyosin and troponin) was lower than that of unregulated actomyosin (containing actin devoid of the regulatory proteins) when the ionic strength was high (> 0 .0 3 ᴍ KCl). At low ionic strength (0.03 ᴍ KCl) the ATPase activity of regulated actomyosin was similar to or even higher than that of unregulated acto­ myosin. Besides increasing ionic strength an increasing actin-myosin ratio tended to depress the ATPase activity of regulated actomyosin below that of unregulated one. At lower ATP concen­ trations (0.1 mᴍ or lower) the ATPase activity of regulated actomyosin was higher than that of unregulated actomyosin at any ionic strength and at any actin-myosin ratio. EGTA inhibited the ATPase of regulated actomyosin under any conditions at high ATP concentrations. At lower ATP concentrations EGTA inhibited either at higher ionic strength or at a higher actin-myosin ratio. The inhibition of the ATPase activity of acto-HMM by increasing ionic strength was not in­ fluenced by the regulatory proteins. - For the interpretation of these results it has been assumed that in actomyosin regulated actin can adopt three states: A low-affinity state which activates the ATPase of myosin only slightly (occurring at high ATP concentrations and in the absence of Ca2+), a high affinity state which activates the ATPase of myosin better than does unregulated actin (occurring at low concentrations of ATP and in the presence of Ca2+), and an intermediate state. This latter state (occurring at high concentrations of ATP and in the presence of Ca2+ or at low concentrations of ATP and in the absence of Ca2+) activates the ATPase of myosin less than does unregulated actin when the actin-myosin ratio is high (wide spacing of myosin on the actin filaments) but activates more (or at least not less) when the actin-myosin ratio is low (dense spacing of myosin on the actin filaments)

Conformational Transitions in Escherichia coli Ribosomal RNAs as Visualized by Dedicated STEM

1988 ◽  
Vol 46 ◽  
pp. 176-177
Author(s):  
J.S. Wall ◽  
V. Maridiyan ◽  
S. Tumminia ◽  
J. Hairifeld ◽  
M. Boublik
Keyword(s):  
Ionic Strength ◽  
Three Dimensional ◽  
Conformational Transitions ◽  
Dark Field ◽  
Dimensional Structure ◽  
Ribosomal Rnas ◽  
Field Mode ◽  
Freeze Dried ◽  
High Resolution Images ◽  
Low Ionic Strength

The high contrast in the dark-field mode of dedicated STEM, specimen deposition by the wet film technique and low radiation dose (1 e/Å2) at -160°C make it possible to obtain high resolution images of unstained freeze-dried macromolecules with minimal structural distortion. Since the image intensity is directly related to the local projected mass of the specimen it became feasible to determine the molecular mass and mass distribution within individual macromolecules and from these data to calculate the linear density (M/L) and the radii of gyration.2 This parameter (RQ), reflecting the three-dimensional structure of the macromolecular particles in solution, has been applied to monitor the conformational transitions in E. coli 16S and 23S ribosomal RNAs in solutions of various ionic strength.In spite of the differences in mass (550 kD and 1050 kD, respectively), both 16S and 23S RNA appear equally sensitive to changes in buffer conditions. In deionized water or conditions of extremely low ionic strength both appear as filamentous structures (Fig. la and 2a, respectively) possessing a major backbone with protruding branches which are more frequent and more complex in 23S RNA (Fig. 2a).

An Evaluation of a Plasma Fractionation System

1960 ◽  
Vol 4 (01) ◽  
pp. 031-044
Author(s):  
George Y. Shinowara ◽  
E. Mary Ruth
Keyword(s):  
Biological Activity ◽  
Ionic Strength ◽  
Plasma Proteins ◽  
High Concentration ◽  
Significant Evidence ◽  
Native Proteins ◽  
Mobility Data ◽  
Fractionation Procedure ◽  
The Individual ◽  
Low Ionic Strength

SummaryFour primary fractions comprising at least 97 per cent of the plasma proteins have been critically appraised for evidence of denaturation arising from a low temperature—low ionic strength fractionation system. The results in addition to those referable to the recovery of mass and biological activity include the following: The high solubilities of these fractions at pH 7.3 and low ionic strengths; the compatibility of the electrophoretic and ultracentrifugal data of the individual fractions with those of the original plasma; and the recovery of hemoglobin, not hematin, in fraction III obtained from specimens contaminated with this pigment. However, the most significant evidence for minimum alterations of native proteins was that the S20, w and the electrophoretic mobility data on the physically recombined fractions were identical to those found on whole plasma.The fractionation procedure examined here quantitatively isolates fibrinogen, prothrombin and antithrombin in primary fractions. Results have been obtained demonstrating its significance in other biological systems. These include the following: The finding of 5 S20, w classes in the 4 primary fractions; the occurrence of more than 90 per cent of the plasma gamma globulins in fraction III; the 98 per cent pure albumin in fraction IV; and, finally, the high concentration of beta lipoproteins in fraction II.

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