Use of Ultrafiltration on the Analysis of Low Molecular Weight Complexing Molecules. Analysis of Iminodiacetic Acid at Constant Ionic Strength

2001 ◽  
Vol 73 (22) ◽  
pp. 5468-5471 ◽  
Author(s):  
Ignacio Moreno-Villoslada ◽  
Eduardo Quiroz ◽  
Carla Muñoz ◽  
Bernabé L. Rivas
1971 ◽  
Vol 121 (4) ◽  
pp. 613-620 ◽  
Author(s):  
Pearl I. Peterkin ◽  
P. S. Fitt

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.


Blood ◽  
1977 ◽  
Vol 49 (2) ◽  
pp. 209-217
Author(s):  
ME Rick ◽  
DE Wampler ◽  
LW Hoyer

Two forms of rabbit factor VIII procoagulant activity, distinguishable by size on gel filtration and ultracentrifugation, have been identified in normal rabbit plasma. These studies have been carried out with citrate-anticoagulated rabbit plasma obtained by cardiac puncture. Two peaks of factor VIII activity were obtained on agarose gel chromatography, using physiologic ionic strength buffers: a high molecular weight peak eluting at the void volume and a second peak eluting with smaller plasma proteins. The presence of high and low molecular weight factor VIII activities was confirmed by sucrose density gradient centrifugation. The two peaks of factor VIII activity remained distinct when proteolytic inhibitors were added to the plasma and eluting buffers. Both the high and low molecular weight factor VIII procoagulant activities were inhibited by antibodies to human and rabbit factor VIII, and both were activated by thrombin. The identification of size heterogeneity of factor VIII in normal rabbit plasma, in the absence of any modification by ionic strength, may permit more satisfactory study of the relationship of factor VIII size to function.


1978 ◽  
Vol 40 (02) ◽  
pp. 316-325 ◽  
Author(s):  
Ira I Sussman ◽  
Harvey J Weiss

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.


2021 ◽  
Author(s):  
George Northover ◽  
Yiru Mao ◽  
MD Hanif ◽  
Salvador Blasco ◽  
Ramon Vilar ◽  
...  

<div>A wide range of organic ligands are found in the rhizosphere. Two important groups are low-molecular-weight organic acids (LMWOAs) and siderophores. We know that LMWOAs and siderophores coexist in the rhizosphere and it has been proposed that they interact, but it is not clear what controls this. Such knowledge gaps undermine biofortification efforts. In this study test the hypothesis that pH and ionic strength gradients make it possible for LMWOAs and siderophores to function synergistically during micronutrient cycling in the rhizosphere.</div>


1985 ◽  
Vol 86 ◽  
pp. 273-280 ◽  
Author(s):  
Santi Capone ◽  
Alessandro de Robertis ◽  
Concetta de Stefano ◽  
Silvio Sammartano ◽  
Rosario Scarcella ◽  
...  

Blood ◽  
1977 ◽  
Vol 49 (2) ◽  
pp. 209-217 ◽  
Author(s):  
ME Rick ◽  
DE Wampler ◽  
LW Hoyer

Abstract Two forms of rabbit factor VIII procoagulant activity, distinguishable by size on gel filtration and ultracentrifugation, have been identified in normal rabbit plasma. These studies have been carried out with citrate-anticoagulated rabbit plasma obtained by cardiac puncture. Two peaks of factor VIII activity were obtained on agarose gel chromatography, using physiologic ionic strength buffers: a high molecular weight peak eluting at the void volume and a second peak eluting with smaller plasma proteins. The presence of high and low molecular weight factor VIII activities was confirmed by sucrose density gradient centrifugation. The two peaks of factor VIII activity remained distinct when proteolytic inhibitors were added to the plasma and eluting buffers. Both the high and low molecular weight factor VIII procoagulant activities were inhibited by antibodies to human and rabbit factor VIII, and both were activated by thrombin. The identification of size heterogeneity of factor VIII in normal rabbit plasma, in the absence of any modification by ionic strength, may permit more satisfactory study of the relationship of factor VIII size to function.


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