Electric permittivity and dielectric dispersion of low-molecular weight DNA at low ionic strength

1979 ◽  
Vol 10 (1) ◽  
pp. 67-80 ◽  
Author(s):  
Th. Vreugdenhil ◽  
F. van der Touw ◽  
M. Mandel
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Dielectric Dispersion ◽  
Low Molecular Weight ◽  
Electric Permittivity ◽  
Low Ionic Strength

scholarly journals Protein diffusion through charged nanopores with different radii at low ionic strength

2014 ◽  
Vol 16 (39) ◽  
pp. 21570-21576 ◽  
Author(s):  
Pieter Stroeve ◽  
Masoud Rahman ◽  
Lekkala Dev Naidu ◽  
Gilbert Chu ◽  
Morteza Mahmoudi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Protein Diffusion ◽  
Similar Molecular Weight ◽  
Low Ionic Strength ◽  
Charged Membranes ◽  
Pore Permeability

Pore permeability for two similar molecular weight proteins (BSA and BHb) through nanoporous charged membranes at low ionic strength (I = 0.001 M).

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.

scholarly journals Rabbit factor VIII: identification of size heterogeneity

Blood ◽  
1977 ◽  
Vol 49 (2) ◽  
pp. 209-217
Author(s):  
ME Rick ◽  
DE Wampler ◽  
LW Hoyer
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Factor Viii ◽  
Low Molecular Weight ◽  
Gel Chromatography ◽  
Weight Factor ◽  
Rabbit Plasma ◽  
Factor Viii Activity ◽  
Size Heterogeneity ◽  
Two Peaks

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.

Human and Bovine Plasminogen-Free Thrombin, Purified by Means of Gel Filtration and Ion Exchange Chromatography

1966 ◽  
Vol 15 (03/04) ◽  
pp. 501-510 ◽  
Author(s):  
W Berg ◽  
K Korsan-Bengtsen ◽  
J Ygge
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Large Scale ◽  
Gel Filtration ◽  
Trisodium Citrate ◽  
Exchange Chromatography ◽  
Simple Method ◽  
Commercial Preparation ◽  
Usual Manner ◽  
Low Ionic Strength

SummaryA simple method for preparation of plasminogen-free human and bovine thrombin is described.Crude thrombin was prepared in the usual manner from oxalated plasma by means of adsorption on BaSO4, elution with trisodium citrate and activating the eluate from BaSO4 with tissue thromboplastin.This crude thrombin was purified by means of gel-filtration and chromatography on CM-Sephadex A-50.The gel-filtration was performed on three types of Sephadex, G-75, G-50, and G--25. By means of Sephadex G-75 the thrombin was well separated from the main part of inert protein and this type of Sephadex was used for the purification in large-scale. Separation of thrombin from protein of higher molecular weight was also obtained with Sephadex G-50 but not with Sephadex G-25 indicating a molecular weight of thrombin between 4000 and 10,000.The importance of using an elution buffer of sufficient high ionic strength for gel-filtration is shown. A great deal of the thrombin was adsorbed to the Sephadex if the gel-filtration was performed at a too low ionic strength.The final preparation contained 30,000 NIH units of thrombin per mg tyrosin and no detectable plasminogen.The commercial preparation “Topostasine” was also purified in the same manner, but the plasminogen content in “Topostasine” was high and could not be completely separated from thrombin.

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 Production and characterisation of a marine Halomonas surface-active exopolymer

2019 ◽  
Vol 104 (3) ◽  
pp. 1063-1076
Author(s):  
Tony Gutierrez ◽  
Gordon Morris ◽  
Dave Ellis ◽  
Barbara Mulloy ◽  
Michael D. Aitken
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
High Molecular Weight ◽  
Positive Influence ◽  
Contaminated Sites ◽  
Crude Oils ◽  
Magnetic Resonance Spectroscopic Analysis ◽  
Surface Active ◽  
Low Ionic Strength ◽  
Pure Hydrocarbon

AbstractDuring screening for novel emulsifiers and surfactants, a marine gammaproteobacterium, Halomonas sp. MCTG39a, was isolated and selected for its production of an extracellular emulsifying agent, P39a. This polymer was produced by the new isolate during growth in a modified Zobell’s 2216 medium amended with 1% glucose, and was extractable by cold ethanol precipitation. Chemical, chromatographic and nuclear magnetic resonance spectroscopic analysis confirmed P39a to be a high-molecular-weight (~ 261,000 g/mol) glycoprotein composed of carbohydrate (17.2%) and protein (36.4%). The polymer exhibited high emulsifying activities against a range of oil substrates that included straight-chain aliphatics, mono- and alkyl- aromatics and cycloparaffins. In general, higher emulsification values were measured under low (0.1 M PBS) compared to high (synthetic seawater) ionic strength conditions, indicating that low ionic strength is more favourable for emulsification by the P39a polymer. However, as observed with other bacterial emulsifying agents, the polymer emulsified some aromatic hydrocarbon species, as well as refined and crude oils, more effectively under high ionic strength conditions, which we posit could be due to steric adsorption to these substrates as may be conferred by the protein fraction of the polymer. Furthermore, the polymer effected a positive influence on the degradation of phenanthrene by other marine bacteria, such as the specialist PAH-degrader Polycyclovorans algicola. Collectively, based on the ability of this Halomonas high-molecular-weight glycoprotein to emulsify a range of pure hydrocarbon species, as well as refined and crude oils, it shows promise for the bioremediation of contaminated sites.

Properties and characteristics of a bacteriocin-like substance produced by Propionibacterium acnes isolated from dental plaque

1988 ◽  
Vol 34 (12) ◽  
pp. 1344-1347 ◽  
Author(s):  
Greg E. Paul ◽  
S. James Booth
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Dental Plaque ◽  
Propionibacterium Acnes ◽  
Gram Positive ◽  
Gram Negative ◽  
A Cell ◽  
Approximate Molecular Weight ◽  
Low Ionic Strength

A cell-associated bacteriocinlike substance with an approximate molecular weight of 78 000 was isolated from an oral isolate of Propionibacterium acnes. The substance was bacteriostatic and was active against both gram-positive and gram-negative anaerobes. Lysozyme inhibited the activity of the bacteriocinlike substance at low ionic strength.

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