DEFECTS OF VITAMIN K-DEPENDENT FACTORS IN CA(11)-STABILI ZED STRUCTURE

1987 ◽  
Author(s):  
S R Poort ◽  
C Krommenhoek-van Es ◽  
I K van der Linden ◽  
N H van Tilburg ◽  
R M Bertina
Keyword(s):  
Vitamin K ◽  
Genetic Variants ◽  
Protein C ◽  
Conformational Transition ◽  
Oral Anticoagulants ◽  
Indirect Evidence ◽  
Coagulation Factors ◽  
Factor Ix ◽  
Factor Vii ◽  
Factor Ii

Vitamin K-dependent (anti)coagulation factors (factor II, VII, IX, X protein C and S) undergo a conformational transition upon binding of Ca(II), which is a prerequisite for their normal function. Abnormalities in these properties occur during vitamin K deficiency or treatment with anti vitamin K drugs and in some genetic variants of coagulation factors. Immunological assays utilizing antibodies against the Ca(II)-stabilized structure are useful to detect such abnormalities.Starting from specific rabbit antisera antibody populations specific for the Ca(II)-dependent conformation of factor II, VII, IX, X and protein C and S were isolated using immuno-affinity procedures. Subsequently immunoradiometric assays specific for the Ca(II)-dependent (Ca(II)Ag) and Ca(II)-independent (NonCa(II)Ag) conformations of the different proteins were developed. These assays were used for the analysis of plasmas of patients stably treated with oral anticoagulants; Ca(II)Ag, NonCa(II)Ag and their ratio were measured as function of the intensity of the treatment (INR 2.4 to 4.8). The same parameters were measured in plasmas of patients with hereditary coagulation disorders. After treatment with oral anticoagulation with an antivitamin K drug reduced ratios of Ca(II)Ag/-NonCa(II)Ag were observed for factor II, VII, IX, protein C and protein S. However, the actual degree of reduction and its dependence on the intensity of treatment varied for the different vitamin K-dependent proteins. In general Ca(II)Ag levels correspond nicely with the procoagulant activity of the concerning proteins. These data provide indirect evidence for the existence of abnormal (non and/or subcarboxylated) forms of the vitamin K-dependent proteins during oral anticoagulant treatment.Genetic variants with a mutation in one of the sites involved in the formation of the Ca(II)-s tab i1ized structure could be detected for factor IX, factor VII and factor II. However, the extent of reduction of the ratio Ca(II)Ag/-NonCa(II)Ag differed considerably in those variants.

The Inhibitor of Prothrombin Conversion in Plasma of Patients on Oral Anticoagulant Treatment

1981 ◽  
Vol 45 (03) ◽  
pp. 237-241 ◽  
Author(s):  
R M Bertina ◽  
M E J Westhoek-Kuipers ◽  
G H J Alderkamp
Keyword(s):  
Vitamin K ◽  
Spectrophotometric Assay ◽  
Factor Ix ◽  
Factor Vii ◽  
Factor X ◽  
Dilution Curve ◽  
Anticoagulant Treatment ◽  
Oral Anticoagulant Treatment ◽  
Coagulation Assays ◽  
Factor Ii

SummaryPooled plasma of patients under stable oral anticoagulation has been analysed with respect to the presence of the vitamin-K dependent factors (factors II, VII, IX and X). Of all factors 1.5-2 times more antigen than procoagulant activity was present. The concentration of factors II, X (measured spectrophotometrically) and VII is about 0.25 U/ml while factor IX is slightly higher. Coagulation assays of factor X always gave lower values than the spectrophotometric assay. This discrepancy was not influenced by the removal of either factor II-factor VII- or factor IX antigen. However, when the factor X antigen was replaced by normal factor X, all factor X assays gave identical results, indicating that PIVKA X is responsible for these discrepancies. Using the technic of the Thrombotest-dilution curve it was shown that PIVKA X is the factor that causes the abnormal prolongation of ox-brain prothrombin time in these plasmas.

ACUTE INTERRUPTION OF ORAL ANTICOAGULANT THERAPY: A THROMBOTIC RISK?

1987 ◽  
Author(s):  
J Rouvier ◽  
H Vidal ◽  
J Gallino ◽  
M Boccia ◽  
A Scazziota ◽  
...  
Keyword(s):  
Anticoagulant Therapy ◽  
Vitamin K ◽  
Oral Anticoagulant ◽  
Protein C ◽  
Oral Anticoagulant Therapy ◽  
Factor Vii ◽  
Factor X ◽  
Functional Protein ◽  
Thrombotic Risk ◽  
Factor Ii

It is still on discussion how oral anticoagulant therapy must be interrupted. A progressive diminution of drug intake have been proposed in order to avoid a MreboundM of vitamin K-dependent procoagulant factors. At the present, it is well known that coumarin drugs affect not only the biologic activity of factors II, VII, IX and X but also Protein C (PC), an inhibitor of coagulation kinetics, and their cofactor Protein S. With the aim to determine the recovery level of PC in relation with the others vitamin K-dependent factors, the effect of suppression of anticoagulant therapy in patients under chronic treatment with acenocoumarin was studied.Quick time, functional factors II, VII, X (one stage methods), functional PC (Francis method) and immunological Factor II and Protein C (Laurell) were determined before and 36 hours after suspension of acenocoumarin administration.Results showed that: 1) Recovery levels of functional Protein C (increased from 28.55% ±2.57 to 72.64% ±5.9) were significantly higer than functional Factor II (22.09% ±2.34 to 30.73% ±8.64), Factor VII (22.55% ±2.01 to 40.73% ±4.85) and Factor X (23.27% ±2.66 to 39.18% ±3.19). Statistical analysis (Newmann-Keuls test) showed at least a p<0.01 between PC increase and factors II, VII or X increment.2) No significant differences were seen between immunological levels of Factor II before and after suspension of acenocoumarin.3) Levels of immunological PC in patients under anticoagulant therapy were higer than functional PC. After acenocoumarin suppression, not correlation was seen between immunological and functional Protein C recovery.It is concluded that acute suppression of acenocoumarin does not induce a thrombotic tendency because the recuperation of functional Protein C is more important than factors II, VII and X recovery.

Structure of the Human Factor VII Gene

1987 ◽  
Author(s):  
Patrick J O'hara ◽  
Frank A Grant ◽  
A Betty ◽  
J Haldmen ◽  
Mark J Murray
Keyword(s):  
Serine Protease ◽  
Vitamin K ◽  
Protein C ◽  
Tandem Repeats ◽  
Human Factor ◽  
Factor Ix ◽  
Factor Vii ◽  
Factor X ◽  
X Protein ◽  
Additional Exon

Factor VII is a member of a family of vitamin K-dependent, gamma-carboxylated plasma protein which includes factor IX, factor X, protein C, protein S and prothrombin. Activated factor VII (factor Vila) is a plasma serine protease which participates in a cascade of reactions leading to the coagulation of blood. Two overlapping genomic clones containing sequences encoding human factor VII were isolated and characterized. The complete sequence of the gene was determined and found to span 12.8 kilobases. The mRNA for factor VII as demonstrated by cDNA cloning is polyadenylated at multiple sites but contains only one AAUAAA poly-A signal sequence. The mRNA can undergo alternative splicing forming one transcript containing eight segments as exons and another with an additional exon which encodes a larger pre-pro leader sequence. The portion of the pre-pro leader coded for by the additional exon has no known counterpart in the other vitamin K-dependent proteins. The positions of the introns with respect to the amino acid sequence encoded by the eight essential exons of factor VII are the same as those present in factor IX, factor X, protein C and the first three exons of prothrombin. These exons code for domains generally conserved among members of this gene family, including a pre-pro leader (the essential exon la and alternative exon lb), a gamma-carboxylated domain (exons 2 and 3) a growth factor domain (exons 4 and 5) an activation region (exon 6) and a serine protease (exon 8). The corresponding introns in these genes are dissimilar with respect to size and sequence, with the exception of the third intron in factor VII and protein C. Four introns and a portion of exon 8 in factor VII contain regions made up of tandem repeats of oligonucleotide monomer elements. More than a quarter of the intron sequences and more than a third of the 3' untranslated portion of the mRNA transcript consist of these minisatellite tandem repeats. This type of structure is responsible for polymorphisms due to allelic variation in repeat copy number in other areas of the human genome. Tandem repeats can evolve as a result of random crossover in DNA whose sequence is not maintained by selection. This suggests that much of the sequence information present in the introns and untranslated portion of the message is dispensable.

A Plasma Factor Enhances Activity of Vitamin K-Dependent Coagulation Proteins

1983 ◽  
Vol 50 (03) ◽  
pp. 749-752 ◽  
Author(s):  
Michael R Owens ◽  
Catherine D Cimino
Keyword(s):  
Rat Liver ◽  
Vitamin K ◽  
Coagulation Factor ◽  
Coagulation Factors ◽  
Rat Plasma ◽  
Factor Vii ◽  
Coagulation Activity ◽  
Factor Ii ◽  
Plasma Factor ◽  
Coagulation Proteins

SummaryA plasma factor, “coagulopoietin”, present in animals with depleted vitamin K-dependent coagulation factors, appears to enhance activity of these factors in normal animals. We have investigated the effects of “coagulopoietin” on synthesis of certain coagulation proteins by the isolated rat liver perfused for eight hours. Liver donor rats received plasma injections from vitamin K-deficient rats or from normal rats 24 hr before sacrifice. Coagulation activity of Factor VII and Factor II in liver perfusate samples was measured with a coagulation assay; Factor II synthesis was also measured by rocket immunoelectrophoresis and by activation with E. carinatus venom. Cumulative hepatic synthesis of. Factor VII coagulation activity was increased by 43% when rat liver donors received vitamin K-deficient rat plasma compared to normal rat plasma. Cumulative synthesis of Factor II coagulation activity was increased by 51%, but synthesis of the protein measured immunologically or by activation with venom was not affected. The “coagulopoietin” factor in these studies appears to increase measurable coagulation factor activity without increasing total protein synthesis.

Growth Hormone Deficiency Impairs Blood Clotting and Reduces Factor VII Coagulant Activity in Rat

1995 ◽  
Vol 73 (04) ◽  
pp. 626-629 ◽  
Author(s):  
L S G Sävendahl ◽  
K Grankvist ◽  
K G Engström
Keyword(s):  
Growth Hormone ◽  
Platelet Count ◽  
Prothrombin Time ◽  
Vitamin K ◽  
Coagulation Factors ◽  
Factor Ix ◽  
Female Rats ◽  
Hormone Deficiency ◽  
Factor Vii ◽  
Female Rat

SummaryTo investigate pituitary effects on the vitamin K-dependent coagulation factors, female rats were hypophysectomized (hypox) and treated with growth hormone (GH), cortisone, thyroxine, vitamin K, or saline. After 11 days of treatment, the prothrombin time, platelet count, and factors II, VII, IX, and X were determined. The prothrombin time was 52.9 ± 1.2% for control rats and 39.1 ± 0.8% for hypox rats (mean ± SEM; p<0.001). All factors decreased after hypophysectomy, reaching significance for factor VII (from 264 ± 23% to 131 ± 9%; p <0.001) and factor IX (from 28.4 ± 2.2% to 17.1 ± 2.5%; p<0.01) while the platelet count was unaffected. When hypox rats were treated with GH, the prothrombin time increased to 50.9 ± 1.0% (p <0.001) and factor VII to 299 ± 10% (p<0.001). Factor II, IX, and X were slightly increased after GH substitution but not after cortisone, thyroxine, or vitamin K treatment. To summarize, GH is of importance for normal hemostasis in the female rat.

Mutations which Introduce Free Cysteine Residues in the Gla-Domain of Vitamin K Dependent Proteins Result in the Formation of Complexes with α1-Microglobulin

1996 ◽  
Vol 75 (01) ◽  
pp. 070-075 ◽  
Author(s):  
E G C Wojcik ◽  
P Simioni ◽  
M v d Berg ◽  
A Girolami ◽  
R M Bertina
Keyword(s):  
Vitamin K ◽  
Protein C ◽  
Cysteine Residue ◽  
Factor Ix ◽  
Disulphide Bond ◽  
Clotting Factors ◽  
High Molecular Weight Complex ◽  
Low Concentrations ◽  
Gla Domain ◽  
Formation Of Complexes

SummaryWe have previously described a genetic factor IX variant (Cys18→Arg) for which we demonstrated that it had formed a heterodimer with armicroglobulin through formation of a disulphide bond with the remaining free cysteine residue of the disrupted disulphide bond in the Gla-domain of factor IX. Recently, we observed a similar high molecular weight complex for a genetic protein C variant (Arg-1→Cys). Both the factor IX and the protein C variants have a defect in the calcium induced conformation. In this study we show that the aminoterminus of this protein C variant is prolonged with one amino acid, cysteine. This protein C variant, as well as protein C variants with Arg9→Cys and Ser12→Cys mutations which also carry a free cysteine residue, are shown to be present in plasma as a complex with α1-microglobulin. A prothrombin variant with a Tyr44→Cys mutation, had not formed such a complex. Furthermore, complexes between normal vitamin K-dependent clotting factors and α1-microglobulin were shown to be present in plasma at low concentrations. The data suggest that the presence of an unpaired cysteine residue in the propeptide or the N-terminal half of the Gla-domain has strongly promoted the formation of a complex with α1-microglobulin in the variants.

Changes Occurring During Coagulation in Glass. I. Normal Human Blood

1960 ◽  
Vol 4 (01) ◽  
pp. 001-016
Author(s):  
Jessica H. Lewis ◽  
Paul Didisheim ◽  
John H. Ferguson ◽  
Kenichi Hattori
Keyword(s):  
Coagulation Factors ◽  
Factor Ix ◽  
Factor Vii ◽  
Sodium Oxalate ◽  
Factor V ◽  
Rapid Rise ◽  
Rapid Fall ◽  
Glass Tubes ◽  
Normal Human ◽  
The Individual

SummaryNormal whole blood was allowed to stand in glass tubes at 37° C, and the clotting process stopped at various intervals by the addition of sodium oxalate. During the first 15 minutes a marked acceleration of clotting activity was found. Study of the individual coagulation factors showed the following changes: a sustained and rapid fall in platelet count, a sustained and rapid rise in PTC (factor IX), a steady fall in fibrinogen, a more gradual fall in AHF (factor VIII), a rapid rise and subsequent fall in proaccelerin (factor V) activity, a somewhat lesser and slower rise and fall in proconvertin (factor VII) activity, and a slow fall in prothrombin concentration. No changes were noted in Hageman factor or PTA activities.

Dietary Changes in Fasting Levels of Factor VII Coagulant Activity (FVII: C) Are Accompanied by Changes in Factor VII Protein and other Vitamin K-dependent Proteins

1995 ◽  
Vol 73 (02) ◽  
pp. 239-242 ◽  
Author(s):  
E M Bladbjerg ◽  
T Tholstrup ◽  
P Marckmann ◽  
B Sandström ◽  
J Jespersen
Keyword(s):  
Fatty Acids ◽  
Vitamin K ◽  
Protein C ◽  
Saturated Fatty Acids ◽  
Factor Vii ◽  
Dietary Regimen ◽  
Blood Samples ◽  
Dietary Changes ◽  
Coagulant Activity ◽  
Before And After

SummaryThe mechanisms behind dietary effects on fasting coagulant activity of factor VII (FVII: C) are not clarified. In the present study of 15 young volunteers, two experimental diets differing in composition of saturated fatty acids (C18:0 [diet S] or C12:0 + C14:0 [diet ML]) were served for 3 weeks each. Fasting blood samples were collected before and after the dietary regimen and analysed for triglycerides, FVII:C, and protein concentrations of FVII, FII, FX, protein C, CRP, albumin, fibrinogen, and F1+2. FVII:C was significantly reduced on diet S compared with diet ML. This was accompanied by a decrease in FVII protein, F1+2 and the vitamin K-dependent proteins FII, FX, and protein C. In contrast, no changes were observed in triglycerides, FVII:C/FVII: Ag, albumin and CRP. Fibrinogen was increased on diet S compared with diet ML. Our findings suggest that the change in fasting FVII:C was part of a general change in concentrations of vitamin K-dependent proteins.

Coagulation Findings in Rats with Experimental Hypersplenism and Their Changes after Splenectomy and after Administration of Adrenaline

1970 ◽  
Vol 23 (03) ◽  
pp. 593-600
Author(s):  
P Pudlák ◽  
I Farská ◽  
V Brabec ◽  
V Pospíšilová
Keyword(s):  
Factor Viii ◽  
Normal Control ◽  
Normal Values ◽  
Coagulation Factors ◽  
Factor Vii ◽  
Factor V ◽  
Thrombin Time ◽  
Factor Ii ◽  
Recalcification Time

Summary1. The following coagulation changes were found in rats with experimental hypersplenism: a mild prolongation of the recalcification time, shortened times in Quick’s test, a lowered activity in plasma thrombin time and shortened times in the partial thromboplastin test. Concentrations of factor II, V, VII (+X), VIII and X did not differ from those of normal control rats.2. The administration of adrenaline to hypersplenic rats induced the correction of the partial thromboplastin test, Quick’s test and plasma thrombin time to normal values. Concentrations of coagulation factors were not significantly changed. An increase was found in factor V.3. Splenectomy performed in hypersplenic rats was followed by a shortened recalcification time, a prolongation of the partial thromboplastin test and of the test with partial thromboplastin and kaolin. A prolongation was also observed in Quick’s test. Complete correction of plasma thrombin time was not observed. The concentration of factor VII increased.4. The administration of adrenaline to splenectomized rats with experimental hypersplenism did not induce any significant changes with the exception of a corrected plasma thrombin time and a decreased concentration of factor VIII.5. A different reaction of factor VIII to adrenaline in normal and hypersplenic rats is pointed out.

Sign in / Sign up

Export Citation Format

Share Document