Human factor VIII procoagulant activity and phospholipid interaction

1981 ◽  
Vol 678 (1) ◽  
pp. 132-136 ◽  
Author(s):  
A LAJMANOVICH ◽  
G HUDRYCLERGEON ◽  
J FREYSSINET ◽  
G MARGUERIE
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Human Factor Viii

scholarly journals A large region (approximately equal to 95 kDa) of human factor VIII is dispensable for in vitro procoagulant activity.

1986 ◽  
Vol 83 (16) ◽  
pp. 5939-5942 ◽  
Author(s):  
J. J. Toole ◽  
D. D. Pittman ◽  
E. C. Orr ◽  
P. Murtha ◽  
L. C. Wasley ◽  
...  
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Large Region ◽  
Human Factor Viii

Rabbit Antibodies Against the Procoagulant Activity (VIII:C) of Human Factor VIII

1981 ◽  
Vol 46 (04) ◽  
pp. 699-705 ◽  
Author(s):  
T H Tran ◽  
G A Marbet ◽  
F Duckert
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Gel Filtration ◽  
Procoagulant Activity ◽  
Solid Matrix ◽  
Factor Viii Activity ◽  
Physiological Conditions ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Factor Viii Antigen

SummaryThe procoagulant activity VIII:C was separated from factor VIII antigen (VIIIR:Ag) by gel filtration in the presence of 0.25 mol/l calcium chloride. Antibodies (anti-VIII:C) were obtained by immunization of rabbits with VIII:C. The last step of the purification procedure of antibodies consists of an adsorption on VIIIR:Ag-Sepharose 2 BCL as immunoadsorbent to remove contaminating traces of antibodies against VIIIR:Ag. The anti- VIII:C titer remains unchanged during this adsorption (29 Bethesda units per mg). In solution, anti-VIII:C neutralies factor VIII activity (in plasma, cryoprecipitate or in purified form) and the fragment VIII:C without reacting with VIIIR:Ag. Once immobilized on a solid matrix, i.e.2% agarose, it loses over 95% of its inhibitory capacity. The immobilized anti-VIIIR:Ag binds stoichiometrically the antigen and the activity of plasma factor VIII. These results together suggest that factor VIII is composed of 2 different entities, but undissociated under physiological conditions. Immunophysical analyses as a function of pH and temperature of anti-VIII:C and its complex with factor VIII show properties similar to those of homologous antibodies. The antigen determinants of VIII:C (VIII:CAg) are destroyed at low pHs or high temperatures, and VIII:C can no more form a complex with anti-VIII:C. Purified anti-VIII:C is also used in a two-stage assay to detect VIII:CAg or cross-reacting material in some severe haemophiliacs.

Concentration-dependent dissociation of factor VIII in 1 M NaCl

1976 ◽  
Vol 230 (2) ◽  
pp. 434-440 ◽  
Author(s):  
Sussman ◽  
W Rosner ◽  
HJ Weiss
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Gel Filtration ◽  
Procoagulant Activity ◽  
Void Volume ◽  
Gradual Transition ◽  
Human Factor Viii ◽  
Factor Viii Concentrates ◽  
High Concentrations ◽  
Dilution Curves

Plasma, cryoprecipitate, Hemofil, and human factor VIII concentrate were dissolved in 1.0 M NaCl and chromatographed on Bio-Gel A-5m. With high concentrations of factor VIII the activity eluted as a symmetrical peak in the void volume; with a low factor VIII concentration the procoagulant activity was retarded. Dilution curves were performed for several human factor VIII concentrates. When the concentration of factor VIII was decreased, elution patterns showed a gradual transition from a peak in the void volume to a peak with a Ve/Vo of 1.7. Cryoprecipitate exhibited a similar behavior in 1.0 M NaCl, but the percent dissociation was greater than expected at high concentrations of factor VIII. When gel filtration was performed with 0.25 M CaCl2, significant dissociation occurred at all concentrations of factor VIII tested. The behavior of factor VIII in 1.0 M NaCl closely fit a theoretically derived curve for the dissociation of a protein from its binder. We conclude that the dissociation of factor VIII in 1 M NaCl is dependent on the concentration and purification of the procoagulant protein.

scholarly journals Immunologic studies on human factor VIII (anti-hemophilic factor A, AHF) components produced by low-ionic-strength dialysis

Blood ◽  
1976 ◽  
Vol 47 (2) ◽  
pp. 253-264 ◽  
Author(s):  
BN Bouma ◽  
JA van Mourik ◽  
S de Graaf ◽  
JM Hordijk-Hos ◽  
JJ Sixma
Keyword(s):  
Ionic Strength ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Factor Activity ◽  
Human Factor Viii ◽  
Low Ionic Strength ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Since dialysis of human factor VIII against buffers of low ionic strength yielded two distinct components, and since the factor VIII fraction isolated from normal plasma showed von Willebrand factor activity as defined by the corrective effect on abnormal platelet retention and ristocetin aggregation in von Willebrand's disease, the present studies were performed to determine if the correcting activities could be attributed to one or both of the components. Dialysis of factor VIII against buffers of low ionic strength led, however, to a decrease in factor VIII procoagulant activity and the reduction of the correcting activities, which suggested that the intact aggregate was required for procoagulant activity and for von Willebrand factor activity. In this respect dialysis of factor VIII at low ionic strength differed from dissociation at high salt concentrations. The two low ionic strength components were identified by the use of a rabbit antiserum against factor VIII, and could be distinguished on the basis of specific antigenic structures. Dialysis of factor VIII at low ionic strength led to a decrease in antigenic determinants closely related to factor VIII function. Specific antibodies to the low ionic strength components inhibited factor VIII activity in normal plasma, but the residual factor VIII was higher than that after inhibition with antibodies against intact factor VIII. Both antibodies interfered with von Willebrand factor activity.

The effect of carbohydrate depletion on procoagulant activity and in vivo survival of highly purified human factor VIII

1984 ◽  
Vol 800 (2) ◽  
pp. 152-158 ◽  
Author(s):  
Philip J. Fay ◽  
Stephen I. Chavin ◽  
Jane E. Malone ◽  
Duane Schroeder ◽  
Frank E. Young ◽  
...  
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Human Factor Viii ◽  
Carbohydrate Depletion

Effects of Neutral Proteases from Human Leukocytes on Structure and Biological Properties of Human Factor VIII

1980 ◽  
Vol 43 (03) ◽  
pp. 211-217 ◽  
Author(s):  
M Kopeć ◽  
K Bykowska ◽  
S Łopaciuk ◽  
M Jelenska ◽  
J Kaczanowska ◽  
...  
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Progressive Increase ◽  
Biological Properties ◽  
Procoagulant Activity ◽  
Blood Leukocytes ◽  
Electrophoretic Patterns ◽  
Human Factor Viii ◽  
Von Willebrand ◽  
Neutral Proteases

SummaryHuman factor VIII was purified from cryoprecipitate and incubated for up to 24 hours with four neutral proteases of human blood leukocytes, namely, with elastase-like protease (ELP), chymotrypsin-like protease (CLP), collagenase and gelatinase. Electrophoretic patterns showed a reproducible sequence of degradation of factor VIII and of its 230,000 molecular weight subunit by ELP and CLP. Intermediate products were similar but those resulting from exhaustive proteolysis by ELP and CLP differed distinctly from each other. Procoagulant activity of factor VIII was rapidly and completely destroyed by ELP and CLP before visible electrophoretic changes would be detected. No increase in this activity was observed prior to its destruction. Von Willebrand factor (ristocetin cofactor) activity was considerably more resistant to ELP and CLP and declined in rough relation to degradation of highly aggregated forms of factor VIII. ELP and CLP produced a pronounced progressive increase in the Laurell reaction antigen. Normal human plasma showed a high potency to inhibit ELP and CLP. Large doses of these enzymes (300 ug per ml) produced in the plasma medium only a moderate fall in factor VIII procoagulant activity. Collagenase and gelatinase did neither degrade factor VIII nor change its biological properties.

scholarly journals Immunologic studies on human factor VIII (anti-hemophilic factor A, AHF) components produced by low-ionic-strength dialysis

Blood ◽  
1976 ◽  
Vol 47 (2) ◽  
pp. 253-264
Author(s):  
BN Bouma ◽  
JA van Mourik ◽  
S de Graaf ◽  
JM Hordijk-Hos ◽  
JJ Sixma
Keyword(s):  
Ionic Strength ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Factor Activity ◽  
Human Factor Viii ◽  
Low Ionic Strength ◽  
Von Willebrand ◽  
Willebrand Factor

Since dialysis of human factor VIII against buffers of low ionic strength yielded two distinct components, and since the factor VIII fraction isolated from normal plasma showed von Willebrand factor activity as defined by the corrective effect on abnormal platelet retention and ristocetin aggregation in von Willebrand's disease, the present studies were performed to determine if the correcting activities could be attributed to one or both of the components. Dialysis of factor VIII against buffers of low ionic strength led, however, to a decrease in factor VIII procoagulant activity and the reduction of the correcting activities, which suggested that the intact aggregate was required for procoagulant activity and for von Willebrand factor activity. In this respect dialysis of factor VIII at low ionic strength differed from dissociation at high salt concentrations. The two low ionic strength components were identified by the use of a rabbit antiserum against factor VIII, and could be distinguished on the basis of specific antigenic structures. Dialysis of factor VIII at low ionic strength led to a decrease in antigenic determinants closely related to factor VIII function. Specific antibodies to the low ionic strength components inhibited factor VIII activity in normal plasma, but the residual factor VIII was higher than that after inhibition with antibodies against intact factor VIII. Both antibodies interfered with von Willebrand factor activity.

The Fractionation Properties of Human Factor VIII (Antihaemophilic Factor)

1960 ◽  
Vol 04 (02) ◽  
pp. 253-260 ◽  
Author(s):  
Franco Gobbi
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Maximum Yield ◽  
Factor Vii ◽  
Precipitation Method ◽  
Salting Out ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Two Factors ◽  
Thromboplastic Activity

SummaryThe fractionation properties of human Factor VIII (antihaemophilic factor, AHF, antihaemophilic globulin) have been studied using a plasma of congenital afibrinogenaemia as a starting material.From a fibrinogen-free plasma, Factor VIII does not precipitate with ethanol at a final concentration of 8%; on the contrary the maximum yield is reached at an ethanol concentration of 25%.With a precipitation method carried out by a one to ten dilution of plasma with distilled water and acidification by N/10 hydrochloric acid to a pFI 5.2, Factor VIII does not precipitate with the euglobulin fraction; when normal plasma is used, such a precipitation is almost complete.With the salting-out fractionation method by ammonium sulphate, Factor VIII precipitates at a concentration between 25 and 33% of saturation either from fibrinogen-free and from normal human plasma.A non-specific thromboplastic activity appears in the fractions prepared by every method. This activity, which is probably due to the activation of seric accelerators, is easily removed by Al(OH)s adsorption. Thus, in order to insure the specificity of Factor VIII assays, the preliminary adsorption of the fractions is indispensable before testing their antihaemophilic activity.Fibrinogen and Factor VIII have different and definite precipitation patterns. When these two factors are associated the fractionation properties of AHF appear quite modified, showing a close similarity to those of fibrinogen. This fact can explain the technical difficulties encountered in the attempt to purify the antihaemophilic factor, and the lack of reproducible procedures for removing fibrinogen without affecting Factor VII.

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