Human plasma alpha 2-macroglobulin : an inhibitor of plasma kallikrein
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TLDR
The studies suggest that the α2-macroglobulin is a major plasma inhibitor of kallikrein and provide a new example of an interrelationship between the coagulation, fibrinolytic, and kall Kikrein enzyme systems.Abstract:
Activation of plasma kallikrein arginine esterase activity by kaolin resulted in peak activity at 1 min of incubation and a 50% reduction in activity at 5 min in normal plasma, and 30% reduction in the plasma of patients with hereditary angioneurotic edema who lacked the C1 inactivator. The peak esterolytic activity was inhibited by soybean trypsin inhibitor whereas the 5 min activity was resistant to this inhibitor. Acid treatment of normal and hereditary angioneurotic edema plasma destroyed the factor responsible for the fall in esterase activity at 5 min and the factor which rendered the esterase resistant to soybean trypsin inhibitor. Purified alpha(2)-macroglobulin inhibited approximately 50% of the TAMe esterase activity of purified plasma kallikrein without changing its activity toward basic amino acid esters. The interaction between the alpha(2)-macroglobulin and kallikrein resulted in alterations in the gel filtration chromatographic pattern of the TAMe esterase and biologic activity of kallikrein, indicating that kallikrein was bound to the alpha(2)-macroglobulin. The TAMe esterase activity of this complex, isolated by column chromatography, was resistant to C1 inactivator and SBTI. Studies of incubation mixtures of kallikrein, alpha(2)-macroglobulin and C1 inactivator suggested that these inhibitors compete for the enzyme, and that the alpha(2)-macroglobulin partially protects the esterase activity of kallikrein from C1 inactivator. The alpha(2)-macroglobulin isolated from kaolin-activated plasma possessed 240 times the esterolytic activity of the alpha(2)-macroglobulin purified from plasma treated with inhibitors of kallikrein and of its activation. The alpha(2)-macroglobulin blocked the uterine-containing activity and vascular permeability-inducing effects of plasma kallikrein. These studies suggest that the alpha(2)-macroglobulin is a major plasma inhibitor of kallikrein and provide a new example of an interrelationship between the coagulation, fibrinolytic, and kallikrein enzyme systems.read more
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References
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Journal ArticleDOI
Crystalline soybean trypsin inhibitor : ii. general properties.
TL;DR: Crystalline soy protein when denatured is readily digestible by pepsin, and less readily by chymotrypsin and by trypsin, which results in a proportional gain in the inhibiting activity.
Journal ArticleDOI
Antigen-antibody reactions in gels. IV. Types of reactions in coordinated systems of diffusion.
Journal ArticleDOI
The Partial Thromboplastin Time with Kaolin: A Simple Screening Test for First Stage Plasma Clotting Factor Deficiencies
TL;DR: Waaler has demonstrated that long times with normal plasma may be caused by inadequate contact activation of the test plasma when, and it is shown that the partial thromboplastin time technic is not widely used in clinical laboratories.
Journal ArticleDOI
Crystalline soybean trypsin inhibitor
TL;DR: Crystalline soy protein when denatured is readily digestible by pepsin, and less readily by chymotrypsin and by trypsin, which results in a proportional gain in the inhibiting activity.
Journal ArticleDOI
The Control of Dicumarol Therapy and the Quantitative Determination of Prothrombin and Proconvertin
P. A. Owren,Aas Ka +1 more
TL;DR: In this paper, the control of Dicumarol therapy and the Quantitative Determination of Prothrombin and Proconvertin were discussed, and the authors proposed a method for the quantification of ProConvertin and Thrombin.