scholarly journals Role of individual gamma-carboxyglutamic acid residues of activated human protein C in defining its in vitro anticoagulant activity

Blood ◽  
1992 ◽  
Vol 80 (4) ◽  
pp. 942-952 ◽  
Author(s):  
L Zhang ◽  
A Jhingan ◽  
FJ Castellino
Keyword(s):  
Protein C ◽  
Anticoagulant Activity ◽  
Coagulation Factor ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Factor Ix ◽  
Human Protein ◽  
Complete Disappearance ◽  
Carboxyglutamic Acid

Abstract To evaluate the contributions of individual gamma-carboxyglutamic acid (gla) residues to the overall Ca(2+)-dependent anticoagulant activity of activated human protein C (APC), we used recombinant (r) DNA technology to generate protein C (PC) variants in which each of the gla precursor glutamic acid (E) residues (positions 6, 7, 14, 16, 19, 20, 25, 26, and 29) was separately altered to aspartic acid (D). In one case, a gla26V mutation ([gla26V]r-PC) was constructed because a patient with this particular substitution in coagulation factor IX had been previously identified. Two additional r-PC mutants were generated, viz, an r-PC variant containing a substitution at arginine (R) 15 ([R15]r-PC), because this particular R residue is conserved in all gla- containing blood coagulation proteins, as well as a variant r-PC with substitution of an E at position 32 ([F31L, Q32E]r-PC), because gla residues are found in other proteins at this sequence location. This latter protein did undergo gamma-carboxylation at the newly inserted E32 position. For each of the 11 recombinant variants, a subpopulation of PC molecules that were gamma-carboxylated at all nonmutated gla- precursor E residues has been purified by anion exchange chromatography and, where necessary, affinity chromatography on an antihuman PC column. The r-PC muteins were converted to their respective r-APC forms and assayed for their amidolytic activities and Ca(2+)-dependent anticoagulant properties. While no significant differences were found between wild-type (wt) r-APC and r-APC mutants in the amidolytic assays, lack of a single gla residue at any of the following locations, viz, 7, 16, 20, or 26, led to virtual complete disappearance of the Ca(2+)-dependent anticoagulant activity of the relevant r-APC mutant, as compared with its wt counterpart. On the other hand, single eliminations of any of the gla residues located at positions 6, 14, or 19 of r-APC resulted in variant recombinant molecules with substantial anticoagulant activity (80% to 92%), relative to wtr-APC. Mutation of gla residues at positions 25 and 29 resulted in r-APC variants with significant but low (24% and 9% of wtr-APC, respectively) levels of anticoagulant activity. The variant, [R15L]r-APC, possessed only 19% of the anticoagulant activity of wrt-APC, while inclusion of gla at position 32 in the variant, [F31L, Q32gla]r-APC, resulted in a recombinant enzyme with an anticoagulant activity equivalent to that of wtr-APC.

scholarly journals Role of individual gamma-carboxyglutamic acid residues of activated human protein C in defining its in vitro anticoagulant activity

Blood ◽  
1992 ◽  
Vol 80 (4) ◽  
pp. 942-952
Author(s):  
L Zhang ◽  
A Jhingan ◽  
FJ Castellino
Keyword(s):  
Protein C ◽  
Anticoagulant Activity ◽  
Coagulation Factor ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Factor Ix ◽  
Human Protein ◽  
Complete Disappearance ◽  
Carboxyglutamic Acid

To evaluate the contributions of individual gamma-carboxyglutamic acid (gla) residues to the overall Ca(2+)-dependent anticoagulant activity of activated human protein C (APC), we used recombinant (r) DNA technology to generate protein C (PC) variants in which each of the gla precursor glutamic acid (E) residues (positions 6, 7, 14, 16, 19, 20, 25, 26, and 29) was separately altered to aspartic acid (D). In one case, a gla26V mutation ([gla26V]r-PC) was constructed because a patient with this particular substitution in coagulation factor IX had been previously identified. Two additional r-PC mutants were generated, viz, an r-PC variant containing a substitution at arginine (R) 15 ([R15]r-PC), because this particular R residue is conserved in all gla- containing blood coagulation proteins, as well as a variant r-PC with substitution of an E at position 32 ([F31L, Q32E]r-PC), because gla residues are found in other proteins at this sequence location. This latter protein did undergo gamma-carboxylation at the newly inserted E32 position. For each of the 11 recombinant variants, a subpopulation of PC molecules that were gamma-carboxylated at all nonmutated gla- precursor E residues has been purified by anion exchange chromatography and, where necessary, affinity chromatography on an antihuman PC column. The r-PC muteins were converted to their respective r-APC forms and assayed for their amidolytic activities and Ca(2+)-dependent anticoagulant properties. While no significant differences were found between wild-type (wt) r-APC and r-APC mutants in the amidolytic assays, lack of a single gla residue at any of the following locations, viz, 7, 16, 20, or 26, led to virtual complete disappearance of the Ca(2+)-dependent anticoagulant activity of the relevant r-APC mutant, as compared with its wt counterpart. On the other hand, single eliminations of any of the gla residues located at positions 6, 14, or 19 of r-APC resulted in variant recombinant molecules with substantial anticoagulant activity (80% to 92%), relative to wtr-APC. Mutation of gla residues at positions 25 and 29 resulted in r-APC variants with significant but low (24% and 9% of wtr-APC, respectively) levels of anticoagulant activity. The variant, [R15L]r-APC, possessed only 19% of the anticoagulant activity of wrt-APC, while inclusion of gla at position 32 in the variant, [F31L, Q32gla]r-APC, resulted in a recombinant enzyme with an anticoagulant activity equivalent to that of wtr-APC.

DEVELOPMENT OF A PROTEIN C CONCENTRATE

1987 ◽  
Author(s):  
Prabir Bhattacharya ◽  
Carolyn L Orthner ◽  
Dudley K Strickland
Keyword(s):  
Protein C ◽  
Antithrombin Iii ◽  
Activated Protein C ◽  
Protein S ◽  
Exchange Chromatography ◽  
Factor Ix ◽  
Human Protein ◽  
Red Cross ◽  
American Red Cross ◽  
Protein C Concentrate

A Protein C (PC) concentrate may be useful in treating patients with congenital or acquired Protein C deficiencies. A method for preparation of a human Protein C concentrate has been developed using a by-product of American Red Cross Factor IX production as the starting material (Menache et. al. Blood, 64, 1220). Levels of other vitamin K dependent proteins in the Protein C concentrate were measured and found to be <10 units per 100 units of PC, except for Protein S. The level of Protein S as judged by immunological assay was 30 u/100 u PC. Assay of the PC concentrate using chrcmogenic substrates revealed that levels of thrombin, Factor 3�a and Factor IXa were less than 0.006 u/mL. In addition, Antithrombin III and ax -macroglobulin were not detected. The vivo effects of Protein C concentrate and Protein C activated by thrombin have been tested in anesthetized rabbits. Thrombin was removed from the activated Protein C by ion-exchange chromatography; depletion was verified by S-2238 or by a clotting assay (< 0.006 u/mL). Rabbits were injected with Protein C concentrate (400 ug/kg) or activated Protein C 24 - 48 ug/Kg). The activated partial thromboplastin time (APTT), FactorV (FV) and Factor VIII (FVIII) levels were measured in samples collected over the next three hours. Infusion of PC concentrate elevated the level of PC to 150% of the preinfusion level within 30 min. It did not change the levels of FV, FVIII, fibrinogen or platelet count. In contrast, infusion of activated Protein C produced progressive prolongation of the APTT. Levels of FV and FVIII were decreased to 25% and 50% of preinfusion levels, respectivelv, three hours after the infusion. Fibrinogen and platelet levels were unchanged during that period. These data demonstrate that activated human Protein C concentrate induces an anticoagulant effect that can be readily measured in rabbits.

Properties of a Recombinant Chimeric Protein in which the gamma-Carboxyglutamic Acid and Helical Stack Domains of Human Anticoagulant Protein C Are Replaced by those of Human Coagulation Factor VII

1997 ◽  
Vol 77 (05) ◽  
pp. 0926-0933 ◽  
Author(s):  
Jie-Ping Geng ◽  
Francis J Castellino
Keyword(s):  
Metal Ion ◽  
Protein C ◽  
Anticoagulant Activity ◽  
Chimeric Protein ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Wild Type ◽  
Coagulation Factor Vii ◽  
Carboxyglutamic Acid ◽  
Wild Type Counterpart

SummaryA chimeric cDNA, encoding residues 1-46 (the γ-carboxyglutamic acid module and its trailing helical stack) of human coagulant factor (f) VII, bound to residues 47-419 of human anticoagulant protein C (PC), was constructed and expressed. The resulting protein, r-[∆GD-HSPC/∇GD-HSfVII]PC, was properly processed with regard to signal/ propeptide release, cleavage of the K156R dipeptide, Gla and Hya contents, and the presence of glycosylation.The mutant protein displayed normal dependencies on Ca2+ for adoption of its metal ion-dependent conformation and for binding to acidic phospholipid vesicles. The chimera failed to recognize a monoclonal antibody (MAb) specific for the Ca2+-induced conformation of the Gla domain (GD) of PC, but did react with another MAb directed in part to the Ca2+-dependent conformation of the GD of fVII. Further, this chimeric protein possessed similar steady state constants as wild-type r-PC toward activation by thrombin and thrombin/thrombomodulin. The activated form of the chimera was very similar to that of its wild- type counterpart in its whole plasma anticoagulant activity, as well as its activity toward inactivation of coagulation factor VIII. The chimeric protein did not bind to the fVII cofactor, tissue factor, showing that the GD/HS domain region of fVII is insufficient for that particular interaction.The results demonstrate that the GD/HS of fVII, when present in the PC and APC background, serves to maintain the Ca2+/PL-related functions of these latter proteins, and suggest that the Ca2+ and PL- dependent interactions of the GD-HS of PC are sufficiently general in nature such that the GD-HS regions of other proteins of this type can satisfy most of the requirements of PC and APC. The data presented also offer support for the independent nature of the domain unit consisting of the GD/HS module.

Construction, Expression, and Properties of a Recombinant Chimeric Human Protein C with Replacement of Its Growth Factor-like Domains by Those of Human Coagulation Factor IX

Biochemistry ◽  
1994 ◽  
Vol 33 (3) ◽  
pp. 823-831 ◽  
Author(s):  
Shiqin Yu ◽  
Li Zhang ◽  
Ashish Jhingan ◽  
William T. Christiansen ◽  
Francis J. Castellino
Keyword(s):  
Growth Factor ◽  
Protein C ◽  
Coagulation Factor ◽  
Factor Ix ◽  
Human Protein ◽  
Coagulation Factor Ix

scholarly journals Antithrombotic Efficacy in the Guinea Pig of a Derivative of Human Protein C With Enhanced Activation by Thrombin

Blood ◽  
1997 ◽  
Vol 89 (2) ◽  
pp. 534-540 ◽  
Author(s):  
Ken D. Kurz ◽  
Tommy Smith ◽  
Alexander Wilson ◽  
Bruce Gerlitz ◽  
Mark A. Richardson ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Protein C ◽  
Thrombus Formation ◽  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Human Protein ◽  
Coagulation Cascade ◽  
Activation Rate ◽  
Antithrombotic Efficacy

Abstract Conversion by α-thrombin of the zymogen human protein C (HPC) to activated protein C (aPC) is an important physiologic feedback control mechanism for the coagulation cascade. Although activation of HPC by thrombomodulin-bound thrombin is relatively rapid, activation by free thrombin occurs at a significantly slower rate. Previously, we generated a “hyper-activatable” derivative of HPC (FLIN-Q3) with an increased activation rate by free α-thrombin in vitro. In this study, the antithrombotic efficacy of FLIN-Q3 was compared with both native zymogen and aPC in an arteriovenous shunt model of thrombosis in the guinea pig. Recombinant proteins were infused 15 minutes before and throughout a 15-minute period while blood was circulated from carotid to jugular through tubing that enclosed a thread on which fibrin was deposited. Parallel dose-dependent antithrombotic responses were observed. Under these non–steady-state conditions, the calculated infusion doses associated with a 50% reduction of thrombus mass were 2.7, 24, and 250 mg/kg/h for aPC, FLIN-Q3, and HPC, respectively. Thrombus weight correlated inversely with plasma concentration of aPC, measured amidolytically, from either direct infusion of aPC or that generated from the zymogens in the animal, and similarly correlated inversely with anticoagulant activity measured by whole blood aPTT. Neither zymogen form showed significant aPC activity before shunt circulation, suggesting a requirement for exposure to thrombin. After the infusion was discontinued for 15 minutes, a second period of thrombus formation in the shunt demonstrated the ability of zymogen forms of PC, unlike aPC, to provide “on-demand” anticoagulant responses to repeated thrombotic stimuli. Thus, a “hyper-activatable” PC molecule such as FLIN-Q3 may represent a superior form of anticoagulant therapy than either the native zymogen or aPC.

Heparin from bovine intestinal mucosa: Glycans with multiple sulfation patterns and anticoagulant effects

2012 ◽  
Vol 107 (05) ◽  
pp. 903-915 ◽  
Author(s):  
Ana M. F. Tovar ◽  
Nina V. M. Capillé ◽  
Gustavo R. C. Santos ◽  
Bruno C. Vairo ◽  
Stephan-Nicollas M. C. G. Oliveira ◽  
...  
Keyword(s):  
Anticoagulant Activity ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Bleeding Tendency ◽  
Structural Components ◽  
Individual Fraction ◽  
Nmr Data ◽  
In Vivo Effects

SummaryPharmaceutical grade heparins from porcine intestine and bovine lung consist mainly of repeating tri-sulfated units, of the disaccharide →4-α-IdoA2S-1 →4-α-GlcNS6S-1 →. Heparin preparations from bovine intestine, in contrast, are more heterogeneous. Nuclear magnetic resonance (NMR) and disaccharide analysis after heparinase digestions show that heparin from bovine intestine contains α-glucosamine with significant substitutive variations: 64% are 6-O-sulfated and N-sulfated, as in porcine intestinal heparin while 36% are 6-desulfated. Desulfated α-iduronic acid units are contained in slightly lower proportions in bovine than in porcine heparin. NMR data also indicate N-, 3-and 6-trisulfated a-glucosamine (lower proportions) and α-GlcNS-1→4-α-GlcA and α-IdoA2S-1→4-α-GlcNAc (higher amounts) in bovine than in porcine heparin. Porcine and bovine heparins can be fractionated by anion exchange chromatography into three fractions containing different substitutions on the a-glucosamine units. Each individual fraction shows close disaccharide composition and anticoagulant activity, regardless of their origin (bovine or porcine intestine). However, these two heparins differ markedly in the proportions of the three fractions. Interestingly, fractions with the typical he-parin disaccharides of porcine intestine are present in bovine intestinal heparin. These fractions contain high in vitro anticoagulant activity, reduced antithrombotic effect and high bleeding tendency. These observations indicate that the prediction of haemostatic effects of heparin preparations cannot rely exclusively on structural analysis and anticoagulant assays in vitro. Minor structural components may account for variations on in vivo effects. In conclusion, we suggest that pharmaceutical grade bovine intestinal heparin, even after purification procedures, is not an equivalent drug to porcine intestinal heparin.

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