scholarly journals STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA

1952 ◽  
Vol 96 (4) ◽  
pp. 319-329 ◽  
Author(s):  
Oscar D. Ratnoff ◽  
Keyword(s):  
Human Plasma ◽  
Calcium Ions ◽  
Proteolytic Enzyme ◽  
Biological Significance ◽  
Globulin Fraction

Calcium ions accelerated the activation of the proteolytic enzyme of plasma from its precursor in the globulin fraction. Calcium did not appear to potentiate fibrinolysis by active bovine or human plasma proteolytic enzyme, nor did it accelerate the activation of the precursor of this enzyme by chloroform or by streptokinase. Experiments with partially purified plasma proteolytic enzyme suggested that the acceleratory effect of calcium was mediated indirectly. Since the concentration of calcium which was effective was comparable to that present in plasma, it is possible that the phenomena reported are of biological significance.

scholarly journals STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA

1950 ◽  
Vol 91 (2) ◽  
pp. 123-133 ◽  
Author(s):  
Oscar D. Ratnoff ◽  
Robert C. Hartmann ◽  
C. Lockard Conley
Keyword(s):  
Human Plasma ◽  
Proteolytic Activity ◽  
Proteolytic Enzyme ◽  
Globulin Fraction ◽  
Considerable Potential ◽  
Normal Platelet

A fraction of globulin was prepared from human plasma which was deficient in prothrombin, thrombin, fibrinogen, plasma thromboplastin, and accelerator globulin. The preparation of globulin contained considerable potential proteolytic activity which could be activated by streptococcal fibrinolysin. This fraction of globulin accelerated the clotting of normal platelet-deficient plasma. However, the clot-accelerating effect of the globulin fraction was the same whether or not its proteolytic property had been activated. The addition of streptococcal fibrinolysin to normal platelet-deficient plasma did not accelerate coagulation. Nor did the addition of streptococcal fibrinolysin to hemophilic platelet-deficient plasma promote its coagulation. The data presented suggest that proteolysis by activated plasma proteolytic enzyme is not an essential stage in the coagulation of the blood.

scholarly journals STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA

1948 ◽  
Vol 87 (3) ◽  
pp. 199-209 ◽  
Author(s):  
Oscar D. Ratnoff
Keyword(s):  
Human Plasma ◽  
Proteolytic Enzyme

1. The experiments reported suggest that the plasma proteolytic enzyme activated by streptococcal fibrinolysin is identical with that activated by chloroform. 2. The precursor of this plasma proteolytic enzyme is precipitated with the euglobulin fraction of plasma at pH 5.2.

scholarly journals Interaction of soluble fibroblast surface antigen with fribrinogen and fibrin.

1975 ◽  
Vol 141 (2) ◽  
pp. 497-501 ◽  
Author(s):  
E Ruoslahti ◽  
A Vaheri
Keyword(s):  
Human Plasma ◽  
Low Temperatures ◽  
Serum Proteins ◽  
Biological Significance ◽  
Cell Type ◽  
Fold Enrichment ◽  
Glycoprotein Antigen ◽  
A Cell ◽  
Cell Type Specific ◽  
Cold Insoluble Globulin

A cell-type specific glycoprotein antigen (SFA) from fibroblast surface appears in human plasma and serum. The amount of SFA in serum was reduced if the blood coagulation clot was removed at a low temperature. SFA could be bound to Sepharose-conjugated fibrinogen and to fibrin powder at 0 degrees C and was subsequently released when the temperature was elevated to plus 37 degrees C. This procedure resulted in a 10-fold enrichment of SFA relative to other serum proteins. SFA was found to be concentrated in the cryoprecipitate fraction of human plasma and was copurified with the cold insoluble globulin (CIG) with procedures published for the purification of the latter component. SFA/CIG is not soluble at low temperatures as such and its appearance in the cryoprecipitate fraction of plasma is likely to be due to its affinity to cryofibrinogen evident from these experiments. The biological significance of the interaction of fibroblast surface SFA moleculres with fibrin(ogen) is not known.

scholarly journals Lipases Produce Functionally Intact Subunits of Factor VIII (Antihaemophilic Factor)

1977 ◽  
Author(s):  
M. Furlan ◽  
T. Jakab ◽  
E. A. Beck
Keyword(s):  
Factor Viii ◽  
Human Plasma ◽  
Functional Properties ◽  
Functional Activity ◽  
Proteolytic Enzyme ◽  
Gel Filtration ◽  
Phenylmethylsulfonyl Fluoride ◽  
Triglyceride Lipase ◽  
Ristocetin Cofactor ◽  
Ethylenediamine Tetraacetate

Cryoprecipitates of fresh human plasma were fractionated by gel filtration on Sepharose CL-2B. Factor VIII was eluted in the void volume together with a non-proteolytic enzyme which was capable of degrading factor VIII into smaller subunits. Similar subunits were observed following treatment of factor VIII with a triglyceride lipase from Rhizopus arrhizus. They retained full functional activity (procoagulant and ristocetin cofactor). The subunits reaggregated spontaneously at 37° into a reconstituted complex which remained functionally fully active. The resulting aggregate could be repeatedly dissociated by addition of fresh lipase. The reaggregation process was enhanced by phenylmethylsulfonyl fluoride or ethylenediamine tetraacetate, but was inhibited at 0°. The treatment with lipase renders factor VIII more susceptible towards plasmin which destroys its functional properties.

scholarly journals The interaction of calcium ions with glycocholate micelles in aqueous solution

1979 ◽  
Vol 181 (1) ◽  
pp. 61-66 ◽  
Author(s):  
B W A Williamson ◽  
I W Percy-Robb
Keyword(s):  
Aqueous Solution ◽  
Dissociation Constant ◽  
Calcium Ions ◽  
Biological Significance ◽  
Ion Concentration ◽  
Reversible Binding ◽  
Counter Ion ◽  
Soluble Complexes

The formation of soluble complexes of Ca2+ ions and glycocholate has been demonstrated. The dissociation constant is 26 nmol/litre and a maximum of 2 Ca2+ ions are bound to each glycocholate micelle. The formation of this complex is shown to be reversible. Binding is increased by the introduction of phosphatidylcholine into the micelle; it is decreased by a decrease in pH and by increased counter-ion concentration. The biological significance of these effects is discussed.

scholarly journals Human Prekallikrein (Plasminogen Proactivator): Purification, Characterization and Activation by Activated Factor XII

1977 ◽  
Author(s):  
Bonno N. Bouma ◽  
John H. Griffin
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Clot Lysis ◽  
Factor Xii ◽  
Globulin Fraction ◽  
Factor Xi ◽  
Form Analysis ◽  
Plasminogen Activator Activity ◽  
Fibrin Plate ◽  
Factor Xiia

In order to resolve conflicting reports about the possible identity of prekallikrein and Factor XII-dependent plasminogen proactivator (FXII-PPA), the γ-globulin fractions of prekallikrein-deficient (Fletcher trait) and of normal plasma were assayed for FXII-PPA. Based on both fibrin plate and clot lysis tests, FXII-PPA in the γ-globulin fractions of prekallikrein-deficient plasmas from 2 unrelated patients was undetectable, i.e. <1% of the FXII-PPA in the normal γ-globulin fraction. However, PPA independent of FXII was detected in both the Fletcher and the normal γ-globulin fractions at 4% of the FXII-PPA present in the normal γ-globulin fraction.Human plasma prekallikrein was purified 2,000-fold (specific clotting activity 22 units/mg) and was greater than 95% homogeneous on SDS-gels. FXII-PPA was always copurified with prekallikrein and was totally separated from Factor XI. No Factor XII-dependent or Factor XII-independent plasminogen activator activity was detected in purified Factor XI preparations at 40 units/ml. Purified prekallikrein in its precursor form gave 2 protein bands on SDS-gels at 82,000 and 78,000 MW. Upon reduction, a single 85,000 MW band was observed. Kallikrein and plasminogen activator activity were generated upon incubation with purified human Factor XIIa (28,000 MW form). Analysis of this reaction mixture on SDS-gels without reduction showed 2 bands with apparently identical MW’s as the precursor protein bands, whereas reduction showed cleavage of both protein bands.These results suggest that prekallikrein is identical to FXII-PPA in normal human plasma and that activation of this zymogen by Factor XIIa involves limited proteolytic cleavage.

scholarly journals THE NATURE OF THE VIRUS RECEPTORS OF RED CELLS

1949 ◽  
Vol 89 (2) ◽  
pp. 223-232 ◽  
Author(s):  
George K. Hirst
Keyword(s):  
Influenza Virus ◽  
Human Plasma ◽  
Red Cells ◽  
Globulin Fraction ◽  
Virus Receptors

A substance (VHI) exists in human plasma which inhibits the agglutination of red cells by influenza virus and is distinct from influenza antibody. When plasma is fractionated by alcohol in the cold the VHI comes out mainly with a mixture of lipid-free alpha and beta globulins (fraction IV-4). On further fractionation the activity comes out with a fraction consisting mainly of beta1 globulin (fraction IV-7). Boiling fraction IV-4 or IV-7 after considerable dilution brings about a large increase in the amount of VHI, much more than can be detected in the original plasma. A similar VHI has been extracted from the ghosts of fowl red cells.

scholarly journals STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA

1948 ◽  
Vol 87 (3) ◽  
pp. 211-228 ◽  
Author(s):  
Oscar D. Ratnoff
Keyword(s):  
Human Plasma ◽  
Proteolytic Enzyme ◽  
Enzyme Preparation ◽  
Early Period ◽  
Direct Proportion ◽  
Direct Activation ◽  
Proteolytic Enzyme Preparation

1. Some conditions for the optimal activation of plasma proteolytic enzyme by chloroform have been described. The activation proceeds slowly. The action of chloroform is probably to remove some substance which inhibits or inactivates the plasma proteolytic enzyme preparation, rather than a direct activation of the enzyme. 2. Plasma proteolytic enzyme is activated by filtrates of cultures of beta hemolytic streptococci. When streptococcal fibrinolysin is present in maximally effective amounts, the activation is almost instantaneous. When the globulin is prepared from heated serum or the globulin is treated with chloroform, the activation of enzyme by streptococcal fibrinolysin appears to be catalytic. If the globulin is not so treated, the reaction appears to involve a stoichiometric process. 3. The plasma proteolytic enzyme activated by chloroform or by streptococcal fibrinolysin digests casein in direct proportion to the concentration of enzyme and to the time of digestion, during the early period of incubation. 4. Fibrinolysin-activated enzyme deteriorates rapidly relative to chloroform-activated enzyme. This may be due to the removal by chloroform of some substance which inactivates plasma proteolytic enzyme.

Optical quantification of sodium, potassium, and calcium ions in diluted human plasma based on ion-selective liquid membranes

1991 ◽  
Author(s):  
Ursula E. Spichiger-Keller ◽  
Kurt Seiler ◽  
Kemin Wang ◽  
Gaby Suter ◽  
Werner E. Morf ◽  
...  
Keyword(s):  
Human Plasma ◽  
Calcium Ions ◽  
Liquid Membranes ◽  
Sodium Potassium
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