scholarly journals Activation of Human Factor X

1977 ◽  
Author(s):  
Carolyn L. Orthner ◽  
Sam Morris ◽  
David P. Kosow
Keyword(s):  
Molecular Weight ◽  
Heavy Chain ◽  
Gel Electrophoresis ◽  
Human Factor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Coagulation Cascade ◽  
Molecular Forms ◽  
Factor X

Factor X is the zymogen of the proteolytic coagulation enzyme Factor Xa. Since the activation of Factor X to Factor Xa may be a rate limiting step of the coagulation cascade we have begun investigations of the mechanism of this reaction. Human Factor X has been purified 6000-fold from human plasma and the final product is over 95% pure as judged by Polyacrylamide gel electrophoresis. Human Factor X has a monomeric molecular weight of 75,000 and consists of two chains held together by a disulphide bridge. The molecular weight of the heavy chain is 56,000 and that of the light chain is 17,500. The venom coagulant protein of V. russelli (RVV-X) activates human Factor X by cleaving the heavy chain. When fully activated, human Factor Xa shows two bands on Polyacrylamide gel electrophoresis indicating that human Factor Xa like the bovine enzyme has two molecular forms.The kinetic mechanism of the activation reaction has been investigated utilizing the chromogenic Factor Xa substrate Bz-Ile-Glu-Gly-Arg-p-Nitroanilide (S-2222). The reaction has an absolute requirement for Ca; Mg cannot substitute for Ca, however Mg can increase the Vmax of Xa formation in the presence of suboptimal concentrations of Ca. Both Ca and Mg effects exhibit positive cooperativity. Our data indicate that human Factor X has at least three cooperative metal binding sites some of which are specific for Ca.

Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

Prothrombin Metz: Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M.J. Rabiet ◽  
J. Elion ◽  
D. Labie ◽  
F. Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS Polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion.Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Va1-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin 1 (P1) and the appearance of abnormal intermediates migra-ti ng faster than P1.

Purification Of Factors IX And X From Clinical Concentrate

1981 ◽  
Author(s):  
G C Russell ◽  
G Kemble ◽  
E G D Tuddenham
Keyword(s):  
Molecular Weight ◽  
Affinity Chromatography ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Polyacrylamide Gel ◽  
Single Band ◽  
Factor Ix ◽  
Factor X ◽  
Clinical Factor

Human factors IX and X have been purified to homogeneity from clinical factor IX concentrate that had been rejected for therapeutic use due to particulate contamination. (It was necessary to start with this material since in the UK, plasma is not commercially available). The procedure involved barium citrate adsorption followed by ammonium sulphate elution, DEAE- cellulose chromatography, gel filtration on Sephacryl S-200 and affinity chromatography on heparin sepharose gel. The preparation of factor IX at this stage showed a single band on SDS-polyacrylamide gel electrophoresis, of molecular weight 58,000. No change in molecular weight was observed in the presence of 2-mercaptoethanol. A further affinity chromatography column - poly (homoarginine) Sepharose or dextran sulphate sepharose - was necessary to obtain homogeneous factor X. The preparation obtained showed a single band on SDS-polyacrylamide gel electrophoresis of molecular weight 67,000. In the presence of 2-mercaptoethanol, two bands were obtained of molecular weights 49000 and 17000 representing the heavy and light chains respectively of factor X. The purified coagulation proteins contained no activated species detectable by nonactivated partial thromboplastin time or by chromogenic substrate (S2222) assay. Prothrombin protein Sand protein C are by-products of this purification procedure.

scholarly journals Isolation and Properties of the Abnormal Factor IX Molecule of Hemophilia BM

1977 ◽  
Author(s):  
B. Østerud ◽  
K. Lavine ◽  
C. K. Kasper ◽  
S. I. Rapaport
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Heavy Chain ◽  
Active Site ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Factor Ix ◽  
Procoagulant Activity ◽  
Ca Ions

Abnormal factor IX from a hemophilia Bm patient (F. IX-Bm) has been isolated to homogeneity on SDS Polyacrylamide gel electrophoresis by the same technique utilized for purifying normal F. IX. F. IX-Bm generated no measurable procoagulant activity when incubated with F. XIa in a two-stage F. IXa assay (normal F. IX, 55 sec; F. IX-Bm, >30 min).F. IX-Bm inhibited the activation of F. X by F. VII and ox brain thromboplastin as measured in an amidolytic assay for factor Xa. Normal F. IX also inhibited this reaction but to a five times lesser degree. F. IX-Bm has the same molecular weight on SDS gel electrophoresis as normal F. IX (55,000) and does not differ from normal F. IX in its amino acid composition. F. XIa cleaves F. IX-Bm in the presence of Ca ions at the same rate as it cleaves normal F. IX, yielding a heavy chain of 27,000 molecular weight and a light chain of 16,000 molecular weight. However, the cleavage does not give rise to procoagulant activity. Like normal F. IXa, the cleaved forms of F. IX-Bm appear to bind phospholipid since F. IX-Bm protein was precipitated with phospholipid in the presence of Ca ions. These data support an hypothesis that the abnormality in the F. IX-Bm molecule stems from a defect at the active site.

scholarly journals Identification of molecular forms of plasminogen and plasmin-inhibitor complexes in urokinase-activated human plasma

1984 ◽  
Vol 223 (1) ◽  
pp. 169-177 ◽  
Author(s):  
S Müllertz ◽  
S Thorsen ◽  
L Sottrup-Jensen
Keyword(s):  
Acetic Acid ◽  
Human Plasma ◽  
Heavy Chain ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Molecular Forms ◽  
Low Grade ◽  
Plasmin Inhibitor

Urokinase-activated human plasma was analysed by acetic acid/urea/polyacrylamide-gel electrophoresis. The bands representing plasminogen, the plasmin-alpha 2-plasmin inhibitor and plasmin-alpha 2-macroglobulin complexes were identified by immunoprecipitation with specific antibodies and by comparison with purified components. Plasminogen and the plasmin-inhibitor complexes were isolated from plasma or thrombin-clotted plasma containing 125I-labelled Glu-plasminogen (residues 1-790) and urokinase. The plasma was kept at 37 degrees C for 0.5 and 10 times the lysis time of the clotted plasma, the clotted plasma until lysis. The plasmin heavy chain from the plasmin-inhibitor complexes was subsequently prepared. Only in one case could a low-grade proteolytic conversion of Glu- forms into Lys/Met/Val-forms (residues 77-790, 68-790 and 78-790 respectively) during the preparations be detected. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and N-terminal sequence analysis of the purified plasminogen and plasmin heavy chain showed the following. The plasminogen in plasma was on the Glu- form. Glu-plasmin constituted 0.74 and 0.58 of the plasmin bound to the alpha 2-plasmin inhibitor in plasma after brief and prolonged activation respectively. The rest was Lys/Met/Val-plasmin. The clotted plasma contained about equal amounts of Glu-plasminogen and Lys/Met/Val-plasminogen, and predominantly Lys/Met/Val-plasmin complexed to alpha 2-plasmin inhibitor and alpha 2-macroglobulin. The results of the analysis of the purified material substantiated the identity of radioactive protein bands in the gel after acetic acid/urea/polyacrylamide-gel electrophoresis.

Purification and partial characterization of cysteine-glutamate transaminase from rat liver

1977 ◽  
Vol 55 (9) ◽  
pp. 958-964 ◽  
Author(s):  
M. P. C. Ip ◽  
R. J. Thibert ◽  
D. E. Schmidt Jr.
Keyword(s):  
Molecular Weight ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Liver Homogenate ◽  
Polyacrylamide Gel ◽  
Gel Chromatography ◽  
Labile Hydrogen ◽  
Apparent Homogeneity

Cysteine-glutamate transaminase (cysteine aminotransferase; EC 2.6.1.3) has been purified 149-fold to an apparent homogeneity giving a specific activity of 2.09 IU per milligram of protein with an overall yield of 15%. The isolation procedures involve the preliminary separation of a crude rat liver homogenate which was submitted sequentially to ammonium sulfate fractionation, TEAE-cellulose column chromatography, ultrafiltration, and isoelectrofocusing. The final product was homogenous when examined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). A minimal molecular weight of 83 500 was determined by Sephadex gel chromatography. The molecular weight as estimated by polyacrylamide gel electrophoresis in the presence of SDS was 84 000. The purified enzyme exhibited a pH optimum at 8.2 with cysteine and α-ketoglutarate as substrates. The enzyme is inactivated slowly when kept frozen and is completely inactivated if left at room temperature for 1 h. The enzyme does not catalyze the transamination of α-methyl-DL-cysteine, which, when present to a final concentration of 10 mM, exhibits a 23.2% inhibition of transamination of 30 mM of cysteine. The mechanism apparently resembles that of aspartate-glutamate transaminase (EC 2.6.1.1) in which the presence of a labile hydrogen on the alpha-carbon in the substrate is one of the strict requirements.

scholarly journals Studies on human pregnancy-associated plasma protein A. Purification by affinity chromatography and structural comparisons with α2-macroglobulin

1980 ◽  
Vol 191 (3) ◽  
pp. 799-809 ◽  
Author(s):  
R G Sutcliffe ◽  
B M Kukulska-Langlands ◽  
J R Coggins ◽  
J B Hunter ◽  
C H Gore
Keyword(s):  
Molecular Weight ◽  
Affinity Chromatography ◽  
Plasma Protein ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein A ◽  
Carbohydrate Content ◽  
Polyacrylamide Gel ◽  
Gel Chromatography ◽  
Tryptic Fragment

Pregnancy-associated plasma protein-A (PAPP-A) has been purified by a combination of methods including antibody-affinity chromatography. The resultant protein, obtained in 16% yield from maternal serum, appeared as a single major component on non-denaturing polyacrylamide and SDS/polyacrylamide gel electrophoresis. The protein showed a single component when analysed by isoelectric focusing under denaturing conditions in the presence and absence of reduction and had a pI of 4.34 and 4.42 respectively. These pI values were indistinguishable from those of alpha 2-macroglobulin (alpha 2M). The molecular weight of the PAPP-A polypeptide as shown by SDS/polyacrylamide-gel electrophoresis was 187000, with a minor component of mol.wt. 82500 that was attributed to proteolysis. Since native PAPP-A had a molecular weight on gel chromatography very similar to that of alpha 2M (620000–820000), it was concluded that PAPP-A was a homotetramer. In the absence of reduction, a high-molecular-weight (420000) protomer of PAPP-A was found. It was deduced that PAPP-A, like alpha 2M, is a dinner, whose protomers are composed of disulphide-linked polypeptide chains. It was found that the molecular weight of the PAPP-A polypeptide exceeded that of alpha 2M by 3.3%, but that the total carbohydrate content of PAPP-A exceeded that of alpha 2M by 10% and that its neutral carbohydrate content exceeded that of alpha 2M by between 7.4 and 9.0%. The significance of the estimated molecular weights of alpha 2M (181000) and its major tryptic fragments is discussed in the light of published values. A tryptic fragment alpha 2M (82500 mol.wt.) was apparently the same size as the major tryptic fragment of PAPP-A.

Sign in / Sign up

Export Citation Format

Share Document