scholarly journals A Normal Inhibitor of the Blood Coagulation Contact Reaction Product

Blood ◽  
1965 ◽  
Vol 25 (5) ◽  
pp. 712-723 ◽  
Author(s):  
H. L. NOSSEL ◽  
J. NIEMETZ

Abstract A method is described for studying and measuring the activity of a normally occurring inhibitor of the blood coagulation contact reaction product (activated PTA). The inhibitor, stable on storage at -20 C. was inactivated by heating plasma to 56 C. for 30 minutes. The inhibitor was stable between pH 5 and 9. Inhibitory activity was increased by aluminum hydroxide adsorption and not apparently affected by celite exhaustion of plasma. The inhibitor was present in the fraction of plasma precipitated between 55 and 65 per cent ammonium sulphate saturation and migrated with the alpha globulins electrophoretically. The action of the inhibitor was prevented by soy bean trypsin inhibitor. Inhibitory activity was present in serum and in all normal plasma samples examined as well as in plasma from patients deficient in Hageman factor, PTA factor or factors VIII or IX. The physiologic and pathologic significance of this inhibitor remains to be determined.

1966 ◽  
Vol 15 (03/04) ◽  
pp. 542-553 ◽  
Author(s):  
K Egeblad

SummaryThe effect of soy bean trypsin inhibitor (SBTI) on fibrinolysis and blood coagulation was investigated. Clot lysis was recorded by means of thrombelastography. SBTI delays fibrinolysis induced by plasmin and by activators of plasminogen (SK-activator and urokinase). Activator-induced lysis is delayed by a combined effect on activator and plasmin. There appears to exist an equilibrium between highly dissociated compounds of inhibitor with the active agents. The inhibitory effect of SBTI is relatively decreased in clots containing human plasma probably caused by an equilibrium with inhibitory agents in the plasma. SBTI delays thrombin generation in recalcified plasma as well as the effect of thromboplastin, but the effect is weak and requires a concentration 70-100 fold the antifibrinolytic active. The effect on thrombosis is even weaker.


1974 ◽  
Vol 140 (6) ◽  
pp. 1615-1630 ◽  
Author(s):  
Louis W. Heck ◽  
Allen P. Kaplan

Unactivated partial thromboplastin antecedent (PTA) has been purified by sequential chromatography of plasma on quaternary aminoethyl Sephadex, sulphoprophyl Sephadex, Sephadex G-150, and passage over an anti-IgG immunoadsorbant. The preparation gave a single band after alkaline disc gel electrophoresis, sodium dodecyl sulfate (SDS) gel electrophoresis and isoelectric focusing in acrylamide gels and was found to have a mol wt of 175,000 by gel filtration, 163,000 by SDS gel electrophoresis, and an isoelectric point of 8.8–9.4 (peak 9.0–9.1). Pre-PTA was activated directly by activated Hageman factor or by Hageman factor prealbumin fragments. Its coagulant activity was inhibited by DFP, soybean trypsin inhibitor and trasylol but not by lima bean trypsin inhibitor or ovomucoid trypsin inhibitor indicating that activated PTA possesses the same inhibition profile utilizing these reagents as does plasma kallikrein. A major plasma inhibitor of activated PTA was found to be a 65,000 mol wt α-globulin which was isolated free of α1-chymotrypsin inhibitor, inter α-trypsin inhibitor, α2-macroglobulin, and the other known inhibitors of activated PTA, the activated first component of complement (C1 INH), and antithrombin III. Its physicochemical properties were identical to α1-antitrypsin, and it was absent in α1-antitrypsin-deficient plasma thereby identifying this PTA inhibitor as α1-antitrypsin.


1977 ◽  
Vol 37 (01) ◽  
pp. 104-110 ◽  
Author(s):  
Masao Nakahara

SummaryVaried amounts of t-AMCHA or EACA added to non-contact fresh dog plasma generates kininogenase and TAME esterase activities. These phenomena may be abolished by prior addition of lima bean trypsin inhibitor. t-AMCHA or EACA had no effect on partially purified kallikrein, but had a significant inhibitory influence on plasma kininase. The generation of prekallikrein activator with t-AMCHA was ascertained by gel filtration on a Sephadex G-100 column. The blood kinin level increased about 50% one hr after administration of t-AMCHA. It is suggested from these results that t-AMCHA may initiate the true activation of the kallikrein system by activating the Hageman factor.


1979 ◽  
Author(s):  
S Clark ◽  
M Scully ◽  
P Webb ◽  
V Kakkar

A method has been devised for the measurement of endotoxin in plasma using the chromogenic substrate, S2222, a substrate which has been shown to be particularly sensitive to the Limulus Lysate. Time curves of the rate of release of the chromogen in mixtures in which procoagulase activation was concurrent, were complex with a lag phase which was shortened by increasing endotoxin concentrations. At a final concentration of 0.5ng/ml and 370 activation was complete within 60 minutes. The enzyme was inhibited by soya bean trypsin inhibitor but not by pancreatic trypsin inhibitor or hirudin. In the method finally adopted the lysate (25µl) was incubated with endotoxin (E.coli 026.86 Difco) and magnesium chloride (final concentration 33mM) in a total volume of 225µl. After 12 minutes preincubation 165µl of S2222(0.4mM) was added and the increase in abdorbance at 405nm over two minutes measured using an Abbott Biochromatic Analyser 100. Linear assay curves were obtained with final concentration of 0.2 to 2.0ngs endotoxin/ml with ΔOD 405/min of 0.35 at 2.0ng endotoxin/ml of final incubation mixture. ΔOD /min in control tubes were of the order of 0.02. For measurement from plasma samples, endotoxin was first extracted with chloroform. Linear calibration curves were achieved at a concentration of endotoxin of 1 to 5ng/ml of whole blood with a net OD/min at the highest concentration of 0.25.


2021 ◽  
Vol 58 (04) ◽  
pp. 1237-1243
Author(s):  
Bushra Javaid

Protease inhibitors (PIs) are a ubiquitous, diverse group of molecules present in multiple forms in all organisms. These inhibitors inactivate proteases from predators/pathogens in addition to regulating intracellular proteolysis. In addition to intracellular localization, storage organs of plants are also a potential site of protease inhibitors. Proteins with trypsin inhibitory activity were isolated from Nigella sativa seed extracts by ammonium sulphate precipitation. Extraction conditions were optimized by choosing an optimum solvent, temperature and incubation period. The highest inhibitory activity of protein extracts was achieved by using 50 mM Tris buffer as solvent and overnight incubation of the suspension at 4°C. The crude seed extract fractionated at 60% ammonium sulphate concentration exhibited highest trypsin inhibitory activity, i.e., 60.15 ± 2.95 %, which was comparable to soybean trypsin inhibitor used as positive control. Ammonium sulphate precipitation of crude extract yielded 39.83-fold purification. Partially purified trypsin inhibitor exhibited 2.39±0.23 TIU mg-1. Additionally, Nigella sativa protein extracts were also investigated for their health-promoting effects against two important proteases, α- Dipeptidyl peptidase-IV (DPP-IV) and angiotensin-converting enzyme (ACE). Highest inhibitory activity against ACE was shown by the crude extract of N. sativa. Among AS fractions, 30% ammonium sulphate concentration exhibited highest inhibition activity against ACE and DPP-IV. Our results suggest that the widely believed role of N. sativa in control of hypertension may at least be partially shared by inhibition of ACE. This is the first study conducted to evaluate the biological activity of N. sativa protein extracts suggesting a potential use of N. sativa proteins in management of hypertension as well as an important source of trypsin inhibitor. Further identification, purification and characterization of different bioactive compounds from N. sativa are being carried out.


1968 ◽  
Vol 127 (3) ◽  
pp. 411-429 ◽  
Author(s):  
Virginia H. Donaldson

The generation of C'1 esterase activity in siliconed plasma obtained from individuals with hereditary angioneurotic edema in remission tends to occur spontaneously, but can be hastened during its incubation with preparations of activated Hageman factor. This effect of activated Hageman factor could not be shown during its incubation with normal siliconed plasma, nor could consumption of normal serum inhibition of C'1 esterase be clearly shown. Soy bean trypsin inhibitor and heparin could impair this enhanced generation of C'1 esterase but neither inhibits the esterolytic function of C'1 esterase once formed. Trasylol was less effective in blocking this effect of activated Hageman factor. While the mechanism of the effect of activated Hageman factor upon C'1 activation remains obscure, it is apparent that some intermediate steps, possibly involving a kinin-forming system of plasma, may play a role.


1982 ◽  
Vol 47 (02) ◽  
pp. 128-131 ◽  
Author(s):  
F Esnard ◽  
E Dupuy ◽  
A M Dosne ◽  
E Bodevin

SummaryA preliminary characterization of a fibrinolytic inhibitor released by human umbilical vein endothelial cells in primary culture is reported. This molecule of Mr comprised between 2 × 105 and 106 and of μ2 mobility precipitates at 43% ammonium sulphate saturation and is totally adsorbed on Concanavalin A Sepharose 4 B. A possible relationship with a macroglobulins is discussed.


1979 ◽  
Vol 44 (10) ◽  
pp. 3177-3182 ◽  
Author(s):  
Mária Stančíková ◽  
Karel Trnavský

Cathepsin G was isolated from human polymorphonuclear leukocytes and purified by affinity chromatography on Antilysin-Sepharose column. Purified enzyme activated later collagenase isolated from leukocytes. Activation at 36°C was maximal after 30 min incubation. Inhibitors of cathepsin G - soya-bean trypsin inhibitor, diisopropyl phosphofluoridate and Antilysin were active in inhibiting the activation of latent collagenase by cathepsin G.


1955 ◽  
Vol 212 (2) ◽  
pp. 507-514
Author(s):  
Earl W. Davie ◽  
Hans Neurath

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