Preparation and Properties of Human Prothrombin Complex

1970 ◽  
Vol 24 (03/04) ◽  
pp. 325-333 ◽  
Author(s):  
G. H Tishkoff ◽  
L. C Williams ◽  
D. M Brown

SummaryAs a corollary to our previous studies with bovine prothrombin, we have initiated a study of human prothrombin complex. This product has been isolated in crystalline form as a barium glycoprotein interaction product. Product yields were reduced compared to bovine product due to the increased solubility of the barium glycoprotein interaction product. On occasion the crystalline complex exhibited good yields. The specific activity of the crystalline complex was 1851 Iowa u/mg. Further purification of human prothrombin complex was made by removal of barium and by chromatography on Sephadex G-100 gels. The final product evidenced multiple procoagulant activities (II, VII, IX and X). The monomeric molecular weight determined by sedimentation equilibrium in a solvent of 6 M guanidine-HCl and 0.5% mercaptoethanol was 70,191 ± 3,057 and was homogeneous with respect to molecular weight. This product was characterized in regard to physical constants and chemical composition. In general, the molecular properties of human prothrombin complex are very similar to the comparable bovine product. In some preparations a reversible proteolytic enzyme inhibitor (p-aminophenylarsonic acid) was employed in the ultrafiltration step of the purification scheme to inhibit protein degradation.

1976 ◽  
Vol 153 (2) ◽  
pp. 363-373 ◽  
Author(s):  
M J Holroyde ◽  
M B Allen ◽  
A C Storer ◽  
A S Warsy ◽  
J M E Chesher ◽  
...  

A new improved procedure for the purification of rat hepatic glucokinase (ATP-d-glucose 6-phosphotransferase, EC 2.7.1.2) is given. A key step is affinity chromatography on Sepharose-N-(6-aminohexanoyl)-2-amino-2-deoxy-d-glucopyranose. A homogeneous enzyme, specific activity 150 units/mg of protein, is obtained in about 40% yield. The molecular weight of the pure enzyme was determined by several procedures. In particular, sedimentation-equilibrium studies under a variety of conditions indicate a molecular weight of 48000 and no evidence for dimerization; reports in the literature of other values are discussed in the light of this evidence on the pure enzyme. The amino acid composition suggests that hepatic glucokinase is closely related to rat brain hexokinase and also the wheat “light” hexokinases.


1941 ◽  
Vol 24 (3) ◽  
pp. 325-338 ◽  
Author(s):  
Roger M. Herriott

A method has been described for the isolation and crystallization of swine pepsin inhibitor from swine pepsinogen. Solubility experiments and fractional recrystallization show no drift in specific activity. The reversible combination of pepsin with the inhibitor was found to obey the mass law. The inhibitor is quite specific, failing to act on other proteolytic and milk clotting enzymes. The inhibitor is destroyed by pepsin at pH 3.5. Chemical and physical studies indicate that the inhibitor is a polypeptide of approximately 5,000 molecular weight with an isoelectric point at pH 3.7. It contains arginine, tyrosine, but no tryptophane and has basic groups in its structure.


1970 ◽  
Vol 46 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Yutaka Tashiro ◽  
Eiichi Otsuki

Ultracentrifugal analyses of the native silk proteins extracted from the various parts of the middle silk gland of the mature silkworm have revealed that there exist four components with S°20,w values of 10S, 9–10S, 9S, and 4S in the extract. It is suggested that the fastest 10S component is the native fibroin synthesized in the posterior silk gland and transferred to the middle silk gland to be stored there, while the slower three components probably correspond to inner, middle, and outer sericins which were synthesized in the posterior, middle, and anterior portion of the middle silk gland, respectively. Native fibroin solution was prepared from the most posterior part of the middle silk gland. Ultracentrifugal analyses have shown that the solution contains considerable amounts of aggregates in addition to the main 10S component. Treatment with lithium bromide (LiBr), urea, or guanidine hydrochloride solution up to 6 M all have failed to dissociate the 10S component. From the sedimentation equilibrium analyses and partial specific volume of 0.716, the molecular weight of the 10S component of the native fibroin solution was found to be between 3.2 – 4.2 x 105, with a tendency to lie fairly close to 3.7 x 105.


1984 ◽  
Vol 98 (1) ◽  
pp. 214-221 ◽  
Author(s):  
P C Tseng ◽  
M S Runge ◽  
J A Cooper ◽  
R C Williams ◽  
T D Pollard

Acanthamoebe profilin has a native molecular weight of 11,700 as measured by sedimentation equilibrium ultracentrifugation and an extinction coefficient at 280 nm of 1.4 X 10(4) M-1cm-1. Rabbit antibodies against Acanthamoeba profilin react only with the 11,700 Mr polypeptide among all other ameba polypeptides separated by electrophoresis. These antibodies react with a 11,700 Mr polypeptide in Physarum but not with any proteins of Dictyostelium or Naeglaria. Antibody-binding assays indicate that approximately 2% of the ameba protein is profilin and that the concentration of profilin is approximately 100 mumol/liter cells. During ion exchange chromatography of soluble extracts of Acanthamoeba on DEAE-cellulose, the immunoreactive profilin splits into two fractions: an unbound fraction previously identified by Reichstein and Korn (1979, J. Biol. Chem., 254:6174-6179) and a tightly bound fraction. Purified profilin from the two fractions is identical by all criteria tested. The tightly bound fraction is likely to be attached indirectly to the DEAE, perhaps by association with actin. By fluorescent antibody staining, profilin is distributed uniformly throughout the cytoplasmic matrix of Acanthamoeba. In 50 mM KCl, high concentrations of Acanthamoeba profilin inhibit the elongation rate of muscle actin filaments measured directly by electron microscopy, but the effect is minimal in KCl with 2 MgCl2. By using the fluorescence change of pyrene-labeled Acanthamoeba actin to assay for polymerization, we confirmed our earlier observation (Tseng, P. C.-H., and T. D. Pollard, 1982, J. Cell Biol. 94:213-218) that Acanthamoeba profilin inhibits nucleation much more strongly than elongation under physiological conditions.


1973 ◽  
Vol 40 (3) ◽  
pp. 427-440 ◽  
Author(s):  
M. A. Islam ◽  
J. M. V. Blanshard

SummaryA milk-clotting proteolytic enzyme was isolated and purified from the culture filtrate ofBacillus cereusstrain x29 by fractionation with acetone or ammonium sulphate and subsequent column chromatography employing DEAE cellulose and DEAE Sephadex. The purified enzyme was found to be homogeneous by acrylamide gel electrophoresis from pH 3·5 to 8·6, with, a molecular weight of about 50000. The single absorption maximum of the native enzyme was at 277 nm and the value ofat 280 nm was 7·79. Purification resulted in a 9-fold enhancement of activity with 24 % yield. The optimum activity of the enzyme was at pH 8·0 at 40 °C with casein as the substrate. The enzyme was found to be most stable at pH 6·0 and was stable to freezing and freeze-drying. Heavy metal ions were found to inactivate the enzyme, but no metal ion activation was found. Enzyme activity was inhibited irreversibly by EDTA and reversibly by 1,10-phenanthroline. The enzyme has been identified as a Zn-containing neutral protease.


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