Purification of Ristocetin Willebrand Factor (RWF)

1975 ◽  
Author(s):  
J. D. Olson ◽  
D. N. Fass ◽  
W. J. Brockway ◽  
E. J. W. Bowie ◽  
K. G. Mann

A component required for the ristocetin-induced aggregation of platelets was isolated in yields of 20-30% from pooled human and porcine plasma by cryoethanol concentration of the RWF, after removal of the vitamin K dependent coagulation factors on barium citrate. The concentrate was further purified using gel filtration (4% agarose) and ion exchange (DEAE-cellulose) chromatography. Sodium dodecyl sulfate polyacrylamide gels of the isolated factor indicated an apparent molecular weight of greater than 500,000. After reduction of RWF with mercaptoethanol, a single band is resolved with an apparent molecular weight of 230,000. The purified component had no factor VIII procoagulant activity and did not compete for the activity of naturally occurring factor VIII inhibitor (human). Antisera raised in rabbits directed against the purified component inhibited the RWF activity but not the factor VIII procoagulant activity of plasma. Amino acid analysis indicated the presence of all normal amino acids and failed to detect any amino sugar. Analysis of lipid revealed a significant amount of lipid composed of mono, di and triglycerides, cholesterol, cholesterol esters and free fatty acid, with small portions of phospholipids.

1976 ◽  
Vol 156 (1) ◽  
pp. 143-150 ◽  
Author(s):  
R H Quarles

Rats (14 days old) were injected with [14c]fucose and young adult rats with [3H]fucose in order to label the myelin-associated glycoproteins. As previously reported, the major [14C]fucose-labelled glycoprotein in the immature myelin had a higher apparent molecular weight on sodium dodecyl sulphate/polyacrylamide gels that the [3H]fucose-labelled glycoprotein in mature myelin. This predominant doubly labelled glycoprotein component was partially purified by preparative gel electrophoresis and converted to glycopeptides by extensive Pronase digestion. Gel filtration on Sephadex G-50 separated the glycopeptides into several clases, which were designted A,B, C AND D, from high to low molecular weight. The 14C-labelled glycopeptides from immature myeline were enriched in the highest-molecular-weight class A relative to the 3H-labelled glycopeptides from mature myelin. Neuraminidase treatment of the glycoprotein before Pronase digestion greatly decreased the proportion of glycopeptides fractionating in the higher-molecular-weight classes and largely eliminated the developmental differences that were apparent by gel filtration. However, neuraminidase treatment did not decrease the magnitude of the developmental difference revealed by electrophoresing the intact glycoprotein on sodium dodecyl sulphate gels, although it did decrease the apparent molecular weight of the glycoprotein from both the 15-day-old and adult rats by an amount comparable in magnitude to that developmental difference. The results from gel filtration of glycopeptides indicate that there is a higher content of large molecular weight, sialic acid-rich oligosaccharide units in the glycoprotein of immature myelin. However, the higher apparent molecular weight for the glycoprotein from 15-day-old rats on sodium dodcyl sulphate gels is not due primarily to its higher sialic acid content.


1978 ◽  
Vol 40 (02) ◽  
pp. 316-325 ◽  
Author(s):  
Ira I Sussman ◽  
Harvey J Weiss

SummaryWhen gel filtration of factor VIII is performed with buffers of high ionic strength (1.0 M NaCl or 0.25 M CaCl2), the procoagulant activity elutes with proteins of relatively low molecular weight. It has been suggested that in the presence of proteolytic inhibitors, the procoagulant activity would appear at the void volume. To test this hypothesis, chromatography with buffers of high ionic strength was performed in the presence of benzamidine hydrochloride, soy bean trypsin inhibitor, heparin, DFP, and aprotinin. Under all of these conditions, the procoagulant activity continued to elute with proteins of low molecular weight. Similar findings were obtained after chromatographing cryoprecipitate prepared from the plasma of a normal subject who had received heparin. Thus, at present there is no direct evidence to suggest that proteolysis is involved in the dissociation of factor VIII by buffers of high ionic strength.


1981 ◽  
Author(s):  
R E Benson ◽  
W J Dodds

Previous studies demonstrated that plasma from dogs homozygous for von Willebrand’s disease (VWD) without detectable factor VUI-related antigen (VIII:RAg) contained moderate levels of a stable factor VIH-coagulant (VIII:C), which had lower apparent molecular weight and combined with the VIII:RAg of canine hemophilic plasma. We have now compared this VWD-VIII:C to the CaCl2-separated form of VIII:C prepared from normal canine factor VIII. The VWD plasma was fractionated at room temperature by 6% agarose gel filtration in 0.15M NaCl and 0.24M CaCl2 buffers, pH 7.25; the VIII:C eluted in each buffer with a relative elution volume (Ve/Vo) of 1.4. Isolated lower molecular weight VIII:C stabilized with albumin (5 mg/ml) and dialysed free of Ca++ was prepared from normal purified canine factor VIII by elution in 0.24M CaCl2 buffer. This CaCl2~separated VIII:C was rechromatographed in both buffers as above and had a Ve/Vo of 1.9. When the VWD and CaCl2 forms of VIII:C were each combined with canine hemophilic plasma and gel filtered in 0.15M NaCl buffer, the VIII:C’s now appeared at the void volume. These mixtures with 1/10 volume 2.4M CaCl2 added before or after combination were also analyzed in 0.24M CaCl2 buffer. The CaCl2-VIII:C eluted with a Ve/Vo of 1.9 regardless of the order of 2.4M CaCl2 addition, but the VWD-VIII:C eluted with Ve/Vo’s of 1.4 when CaCl2 was added before mixing and 1.9 when added afterwards.Thus, when mixed with hemophilic plasmas both the CaCl2 and VWD forms of VIII:C exhibited similar combination and separation characteristics. However, the finding that the CaCl2-VIII:C is of apparent lower molecular weight than the VWD form suggests that the CaCl2-separated VIII:C is different from the naturally occurring form of VWD (VIII: RAg-free) VIII:C.


Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 310-321 ◽  
Author(s):  
ME Switzer ◽  
PA McKee

Abstract Factor VIII/von Willebrand factor (FVIII/vWF) is a glycoprotein with a molecular weight greater than one-million daltons. Two activities are associated with this large molecule: FVIII procoagulant activity and vWF activity. Incubation of FVIII/vWF with proteolytic enzymes causes rapid inactivation of the FVIII procoagulant activity but has little effect on the vWF activity or antigenicity. In an attempt to gain insight into the structural features required for these two activities, antisera were raised in rabbits to normal, thrombin-inactivated, and plasmin-inactivated FVIII/vWF. All of these proteolytically modified forms of FVIII/vWF cross-reacted with each of the rabbit antisera; each blocked the ability of a human inhibitor to inactivate native active FVIII/vWF. Each of the antisera was a potent inhibitor of vWF activity and inactivated vWF activity at the same titer. The antisera were much less potent inhibitors of FVIII activity than of vWF activity. Antibodies to thrombin-inactivated FVIII/vWF or normal FVIII/vWF had about the same ability to inactivate FVIII procoagulant activity. Surprisingly, those to plasmin-inactivated FVIII/vWF still retained about 50% of this inhibitory capacity. A comparison of the three types of antigens by polyacrylamide gel electrophoresis in sodium dodecyl sulfate-6 M urea demonstrated that the structure of thrombin- inactivated FVIII/vWF was indistinguishable from that of normal FVIII/vWF, while plasmin-inactivated FVII/vWF was completely cleaved to lower molecular weight fragments. Some of the reported variations in the ability of rabbit antibodies to inhibit procoagulant activity may be due to partial degradation of the starting antigen. The retention by FVIII/vWF protein of its immunologic properties even after extensive proteolytic degradation suggests that under nondenaturing conditions, the conformation of the native and degraded molecules are very similar.


1973 ◽  
Vol 135 (2) ◽  
pp. 367-373 ◽  
Author(s):  
C.-C. Liu ◽  
C.-H. Chung ◽  
M.-L. Lee

l-Tryptophan-activating enzyme [l-tryptophan–tRNA ligase (AMP), EC 6.1.1.2] of water-buffalo brain was purified to near homogeneity by heat and pH treatments, ammonium sulphate fractionation, column chromatography on DEAE-cellulose, hydroxyapatite and Amberlite CG-50, and gel filtration on Sephadex G-200. The purified enzyme catalyses tryptophanyl-tRNA formation with yeast tRNA, but not with Escherichia coli tRNA. The enzyme exhibits multiple peaks of activity in Sephadex gel filtration with molecular weights corresponding to 155000, 105000 and 50000. However, only one peak of activity with molecular weight of 155000 can be detected when the enzyme is subjected to gel filtration at high concentration. Disc gel electrophoresis in the presence of sodium dodecyl sulphate reveals a single band with molecular weight of 55000. The activity of the enzyme is concentration dependent. Different Km and Vmax. values are obtained at different enzyme concentrations. These data suggest that this enzyme may exist in different quaternary structures, each with its own kinetic constants. The enzyme activity is inhibited by p-chloromercuribenzoate, and is not protected by the presence of the substrates, l-tryptophan, Mg2+, ATP, in any combination.


1981 ◽  
Vol 197 (2) ◽  
pp. 427-436 ◽  
Author(s):  
G A Nimmo ◽  
J R Coggins

Neurospora crassa contains three isoenzymes of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase, which are inhibited by tyrosine, tryptophan and phenylalanine respectively, and it was estimated that the relative proportions of the total activity were 54%, 14% and 32% respectively. The tryptophan-sensitive isoenzyme was purified to homogeneity as judged by polyacrylamide-gel electrophoresis and ultracentrifugation. The tyrosine-sensitive and phenylalanine-sensitive isoenzymes were only partially purified. The three isoenzymes were completely separated from each other, however, and can be distinguished by (NH4)2SO4 fractionation, chromatography on DEAE-cellulose and Ultrogel AcA-34 and polyacrylamide-gel electrophoresis. Polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate indicated that the tryptophan-sensitive isoenzyme contained one type of subunit of molecular weight 52000. The molecular weight of the native enzyme was found to be 200000 by sedimentation-equilibrium centrifugation, indicating that the enzyme is a tetramer, and the results of cross-linking and gel-filtration studies were in agreement with this conclusion.


1975 ◽  
Vol 151 (3) ◽  
pp. 685-697 ◽  
Author(s):  
M Letarte-Muirhead ◽  
A N Barclay ◽  
A F Williams

The Thy-1-molecule, which was identified by its antigenic activities, has been purified from rat thymocytes. The purification involved preparation of crude membranes and solubilization in deoxycholate, followed by gel filtration and affinity chromatography on antibody or lectin columns. In all cases the purified molecule was a glycoprotein that did not form higher polymers and was not associated with other polypeptide chains. The Thy-1 glycoprotein could be found in two forms, one binding to lentil lectin, the other not. Both forms had the same detectable antigens and were of a similar but not identical size. After sodium dodecyl sulphate-polyacrylamide-gel electrophoresis the apparent molecular weight of Thy-1 binding to lentil lectin was 25 000, whereas that not binding to the lectin was 27 000, with heterogeneity towards forms of apparently higher molecular weight.


1983 ◽  
Vol 61 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Kiyoshi Takeuchi

Exo-β-1,3-glucanase from the sea urchin embryos was purified 114-fold from the initial hatching supernatant by the following procedures: (a) gel filtration on Sephadex G-100; (b) hydrophobic chromatography on 4-phenylbutylamine-Sepharose (PBA-Sepharose); (c) two ion-exchange chromatographic steps on DEAE-cellulose; (d) gel filtration on Ultrogel AcA 34; (e) gel filtration on Sephadex G-100. The purified enzyme contained 2.2% carbohydrate and gave a single protein band corresponding to a molecular weight of 136 000 following electrophoresis on sodium dodecyl sulfate (SDS) – urea – polyacrylamide gel. Gel filtration on Ultrogel AcA 34 with a nondenaturing solvent gave a molecular weight of 130 000 ± 6000. The enzyme displayed an optimum pH at 5.0–5.5 and hydrolysed laminarin and PS(curdlan)-beads at the nonreducing ends, releasing glucose. Although activity of the purified enzyme was not affected by SDS, urea, some divalent ions, and 2-mercaptoethanol, both dithiothreitol and Hg2+ were markedly inhibitory.


Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 310-321
Author(s):  
ME Switzer ◽  
PA McKee

Factor VIII/von Willebrand factor (FVIII/vWF) is a glycoprotein with a molecular weight greater than one-million daltons. Two activities are associated with this large molecule: FVIII procoagulant activity and vWF activity. Incubation of FVIII/vWF with proteolytic enzymes causes rapid inactivation of the FVIII procoagulant activity but has little effect on the vWF activity or antigenicity. In an attempt to gain insight into the structural features required for these two activities, antisera were raised in rabbits to normal, thrombin-inactivated, and plasmin-inactivated FVIII/vWF. All of these proteolytically modified forms of FVIII/vWF cross-reacted with each of the rabbit antisera; each blocked the ability of a human inhibitor to inactivate native active FVIII/vWF. Each of the antisera was a potent inhibitor of vWF activity and inactivated vWF activity at the same titer. The antisera were much less potent inhibitors of FVIII activity than of vWF activity. Antibodies to thrombin-inactivated FVIII/vWF or normal FVIII/vWF had about the same ability to inactivate FVIII procoagulant activity. Surprisingly, those to plasmin-inactivated FVIII/vWF still retained about 50% of this inhibitory capacity. A comparison of the three types of antigens by polyacrylamide gel electrophoresis in sodium dodecyl sulfate-6 M urea demonstrated that the structure of thrombin- inactivated FVIII/vWF was indistinguishable from that of normal FVIII/vWF, while plasmin-inactivated FVII/vWF was completely cleaved to lower molecular weight fragments. Some of the reported variations in the ability of rabbit antibodies to inhibit procoagulant activity may be due to partial degradation of the starting antigen. The retention by FVIII/vWF protein of its immunologic properties even after extensive proteolytic degradation suggests that under nondenaturing conditions, the conformation of the native and degraded molecules are very similar.


1982 ◽  
Vol 62 (3) ◽  
pp. 321-328 ◽  
Author(s):  
Naotika Toki ◽  
Sumiyoshi Takasugi ◽  
Hiroyuki Sumi

1. An elastase-like enzyme in plasma of patients with acute pancreatitis was purified by DEAE-cellulose column chromatography and polyacrylamide-gel disc electrophoresis. 2. In this way 0.24 mg of purified enzyme with a specific activity of 3.94 succinyl-l-alanyl-l-alanyl-l-alanyl-p-nitroanilide units/mg of protein was obtained from 10 ml of plasma. 3. The purified material was homogeneous as ascertained by sodium dodecyl sulphate/polyacrylamide-gel disc electrophoresis and had an apparent molecular weight of 24 000 as measured by gel filtration on Sephadex G-100. 4. This enzyme hydrolysed denatured casein and Congo Red—elastin as well as succinyl-l-alanyl-l-alanyl-l-alanyl-p-nitroanilide. Its amidolytic activity was inhibited by soya bean trypsin inhibitor, but not by aprotinin. 6. We propose that an elastase-like enzyme, probably different from elastase 1 or elastase 2, is liberated from the pancreas into blood during acute pancreatitis and becomes combined with α2-macroglobulin.


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