scholarly journals The effect of ionic strength on enzymatic activity of thrombin

1990 ◽  
Vol 6 (3) ◽  
pp. 59-65 ◽  
Author(s):  
I. V. Pekhnik ◽  
M. Yu. Selishcheva ◽  
A. A. Sereyskaya
Keyword(s):  
Ionic Strength ◽  
Enzymatic Activity

THROMBIN PROPERTIES

1957 ◽  
Vol 35 (1) ◽  
pp. 743-758 ◽  
Author(s):  
Edward Ronwin
Keyword(s):  
Ionic Strength ◽  
Substrate Specificity ◽  
Enzymatic Activity ◽  
Enzymatic Properties ◽  
Organic Reagents

The enzymatic properties of thrombin have been examined and compared with those of two related enzymes, plasmin and trypsin. The effects of factors such as pH, substrate specificity, ionic strength, cations, anions, and organic reagents on the enzymatic activity of thrombin have been studied. While the three enzymes discussed possess differences, such similarities as were observed are quite striking and permit their classification into one group as tryptic enzymes.

Flavobacterium meningosepticum peptide: N-glycosidase: influence of ionic strength on enzymatic activity

1992 ◽  
Vol 24 (1-2) ◽  
pp. 71-79 ◽  
Author(s):  
Sylvie Gosselin ◽  
Brian M. Martin ◽  
Gary J. Murray ◽  
Thammaiah Viswanatha
Keyword(s):  
Ionic Strength ◽  
Enzymatic Activity ◽  
Flavobacterium Meningosepticum

The Association Of Thrombin With Fibrin And Its Solubilization During Plasmic Digestion

1981 ◽  
Author(s):  
Charles W Francis ◽  
Victor J Marder ◽  
Grant H Barlow ◽  
S Eric Martin
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Enzymatic Activity ◽  
Free Enzyme ◽  
Active Enzyme ◽  
Clot Formation ◽  
Human Fibrinogen ◽  
Soluble Fibrin ◽  
Human Thrombin ◽  
Fibrin Clots

It has previously been demonstrated that thrombin binds to fibrin during clot formation. We have studied the nature of this association and the fate of bound thrombin during fibrin degradation by plasmin. Approximately 10% of human thrombin used to clot human fibrinogen bound to the fibrin and could not be removed by washing in buffers of physiologic pH and ionic strength. Plasmic digestion released thrombin into the lysate where it retained enzymatic activity, as measured by chromogenic and clotting assays. The fibrin was degraded to a group of unique degradation complexes of molecular weight between 230,000 and greater than 800,000. The active thrombin was present in the lysate both as free enzyme and bound to certain of these complexes, primarily those larger than 230,000 daltons. At low initial thrombin concentrations, most of the active enzyme released during plasmic digestion was bound to fibrin derivatives, while at higher initial thrombin concentrations, most was released as free enzyme. This suggests that there are at least two types and/or sites of association between thrombin and fibrin. The presence of thrombin on fibrin clots and bound to soluble fibrin derivatives may have pathophysiologic importance in the propagation of thrombi and in the development of hypercoagulable states.

THROMBIN PROPERTIES

1957 ◽  
Vol 35 (9) ◽  
pp. 743-758 ◽  
Author(s):  
Edward Ronwin
Keyword(s):  
Ionic Strength ◽  
Substrate Specificity ◽  
Enzymatic Activity ◽  
Enzymatic Properties ◽  
Organic Reagents

The enzymatic properties of thrombin have been examined and compared with those of two related enzymes, plasmin and trypsin. The effects of factors such as pH, substrate specificity, ionic strength, cations, anions, and organic reagents on the enzymatic activity of thrombin have been studied. While the three enzymes discussed possess differences, such similarities as were observed are quite striking and permit their classification into one group as tryptic enzymes.

The ionic strength dependence of chromatin folding

1978 ◽  
Vol 36 (2) ◽  
pp. 220-221
Author(s):  
F. Thoma ◽  
TH. Koller
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Ionic Strength ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Carbon Supports ◽  
Ionic Strength Dependence ◽  
Chromatin Folding ◽  
Strength Dependence ◽  
Preparation Techniques

Under a variety of electron microscope specimen preparation techniques different forms of chromatin appearance can be distinguished: beads-on-a-string, a 100 Å nucleofilament, a 250 Å fiber and a compact 300 to 500 Å fiber.Using a standardized specimen preparation technique we wanted to find out whether there is any relation between these different forms of chromatin or not. We show that with increasing ionic strength a chromatin fiber consisting of a row of nucleo- somes progressively folds up into a solenoid-like structure with a diameter of about 300 Å.For the preparation of chromatin for electron microscopy the avoidance of stretching artifacts during adsorption to the carbon supports is of utmost importance. The samples are fixed with 0.1% glutaraldehyde at 4°C for at least 12 hrs. The material was usually examined between 24 and 48 hrs after the onset of fixation.

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).

The three-dimensional structure of frozen-hydrated left- and right-handed forms of bacterial flagellar filaments from an identical serotype

1986 ◽  
Vol 44 ◽  
pp. 298-299
Author(s):  
S. Trachtenberg ◽  
D. J. DeRosier
Keyword(s):  
Ionic Strength ◽  
Basal Body ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Protein Species ◽  
Liquid Environment ◽  
Bacterial Flagellum ◽  
Left And Right ◽  
Rotary Motor ◽  
Helical Parameters

The bacterial cell is propelled through the liquid environment by means of one or more rotating flagella. The bacterial flagellum is composed of a basal body (rotary motor), hook (universal coupler), and filament (propellor). The filament is a rigid helical assembly of only one protein species — flagellin. The filament can adopt different morphologies and change, reversibly, its helical parameters (pitch and hand) as a function of mechanical stress and chemical changes (pH, ionic strength) in the environment.

A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg
Keyword(s):  
Enzymatic Activity ◽  
Colorimetric Determination ◽  
Health And Disease ◽  
Urine Serum

Adsorption of chlorate and bromate ions on mercury electrodes from constant ionic strength solutions

1988 ◽  
Vol 85 ◽  
pp. 523-527
Author(s):  
M.M. Zuleika ◽  
Palhares SILVA ◽  
Ernesto Rafael GONZALEZ ◽  
Luis Alberto AVACA ◽  
Artur de Jesus MOTHEO
Keyword(s):  
Ionic Strength ◽  
Constant Ionic Strength ◽  
Mercury Electrodes
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