Fibrinolytic action of an enzyme preparation covalently bound with modified thrombin

SummaryAfter thrombin treatment insolubilized fibrinmonomer, which is obtained from insolubilized fibrinogen covalently bound to agarose, adsorbs soluble fibrin and its derivatives from solutions. The immobilized proteins are attached to the agarose by the ‘A’ αchain. After reduction of the disulfide bridges the β and γchains can be removed from the agarose.After thrombin treatment the immobilized αchain adsorbs fibrinogen and fragment D. To some extent the β and γchain do not seem necessary for the adsorption. The amount adsorbed increases, when thrombin treatment of the insolubilized protein follows the reduction process.This may indicate that the fibrinopeptides ‘A’ of the insolubilized αchain are better accessible after the removal of the β and γchains.

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Impairment of Platelet Aggregation by Echis colorata Venom Mediated by L-Amino Acid Oxidase or H2O2

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657280 ◽

1982 ◽

Vol 48 (03) ◽

pp. 277-282 ◽

Cited By ~ 22

Author(s):

I Nathan ◽

A Dvilansky ◽

T Yirmiyahu ◽

M Aharon ◽

A Livne

Keyword(s):

Hydrogen Peroxide ◽

Amino Acid ◽

Platelet Aggregation ◽

Snake Venom ◽

Oxidase Activity ◽

Enzyme Preparation ◽

Acid Oxidase ◽

Crude Venom ◽

Amino Acid Oxidase ◽

Hemostatic Disorders

SummaryEchis colorata bites cause impairment of platelet aggregation and hemostatic disorders. The mechanism by which the snake venom inhibits platelet aggregation was studied. Upon fractionation, aggregation impairment activity and L-amino acid oxidase activity were similarly separated from the crude venom, unlike other venom enzymes. Preparations of L-amino acid oxidase from E.colorata and from Crotalus adamanteus replaced effectively the crude E.colorata venom in impairment of platelet aggregation. Furthermore, different treatments known to inhibit L-amino acid oxidase reduced in parallel the oxidase activity and the impairment potency of both the venom and the enzyme preparation. H2O2 mimicked characteristically the impairment effects of L-amino acid oxidase and the venom. Catalase completely abolished the impairment effects of the enzyme and the venom. It is concluded that hydrogen peroxide formed by the venom L-amino acid oxidase plays a role in affecting platelet aggregation and thus could contribute to the extended bleeding typical to persons bitten by E.colorata.

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INTERFERENCE BY SERUM PROTEINS WITH LH RADIOIMMUNOASSAY USING IMMUNOSORBENT

Acta Endocrinologica ◽

10.1530/acta.0.0720235 ◽

1973 ◽

Vol 72 (2) ◽

pp. 235-242 ◽

Cited By ~ 11

Author(s):

A. M. Reuter ◽

J. C. Hendrick ◽

J. Sulon ◽

P. Franchimont

Keyword(s):

Molecular Weight ◽

Human Serum ◽

High Molecular Weight ◽

Serum Proteins ◽

Void Volume ◽

High Molecular Weight Proteins ◽

Serum Fractionation ◽

Covalently Bound

ABSTRACT The percentage of LH* bound to antibodies that have been covalently bound to cellulose is diminished in the presence of LH-free human serum and sera from various species of animals. Serum fractionation studies on Sephadex G 200 show that the greatest interference comes from the proteins eluted in the void volume i. e. the high molecular weight proteins. Specifically, the gamma M globulins and the α2-macroglobulins appear to play an important role, as demonstrated by tests in which these proteins were neutralized by gamma M and α2-macroglobulin antisera.

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COMPARISON BETWEEN COVALENTLY BOUND AND FREE ANTIBODIES, USED FOR RADIOIMMUNOASSAY

Acta Endocrinologica ◽

10.1530/acta.0.0680425 ◽

1971 ◽

Vol 68 (3) ◽

pp. 425-430 ◽

Cited By ~ 11

Author(s):

J. Arends

Keyword(s):

Covalently Bound

ABSTRACT Radioimmunoassays using either free or covalently bound antibodies under otherwise identical conditions have been compared. A lowered utilization of antibodies and a loss in sensitivity protential have been observed with the last mentioned method.

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THE INFLUENCE OF ETHANOL ON THE CONVERSION OF PREGNENOLONE TO PROGESTERONE BY HUMAN PLACENTAL MICROSOMES

Acta Endocrinologica ◽

10.1530/acta.0.0760178 ◽

1974 ◽

Vol 76 (1) ◽

pp. 178-188 ◽

Cited By ~ 3

Author(s):

H. Lübbert ◽

K. Pollow ◽

R. Wagner ◽

J. Hammerstein

Keyword(s):

Kinetic Parameters ◽

Enzyme Preparation ◽

Ethanol Concentration ◽

Hydroxysteroid Dehydrogenase ◽

Product Formation ◽

Linear Increase ◽

Maximal Velocity ◽

Microsomal Enzyme ◽

Temperature Optima ◽

Substrate Concentrations

ABSTRACT The effects of ethanol on kinetic parameters of placental Δ5-3β-hydroxysteroid dehydrogenase were studied. In the presence of high pregnenolone concentrations (50 μm, [S] > Km) the microsomal enzyme preparation exhibited an almost linear increase in activity as the ethanol concentration in the medium was raised from 2.5 to 15 % (v/v). At lower substrate concentrations ([S] << Km) ethanol caused inhibition. Other effects of ethanol were: linearity of product formation with time was prolonged; the maximal velocity was markedly increased; the Km for pregnenolone slightly decreased with increasing ethanol concentrations (2.5 to 10 %, v/v) whereas the Km for NAD remained the same. The pH and temperature optima of the reaction were unaffected by ethanol. Other organic solvents caused similar effects.

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Faculty Opinions recommendation of Solution X-ray scattering combined with computational modeling reveals multiple conformations of covalently bound ubiquitin on PCNA.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13365979.14736087 ◽

2011 ◽

Author(s):

Claire Wyman

Keyword(s):

Computational Modeling ◽

X Ray ◽

X Ray Scattering ◽

Multiple Conformations ◽

Covalently Bound ◽

Ray Scattering

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UDP-D-glucose 4-epimerase activity of the tissue culture of white poplars (Populus alba L. var. pyramidalis)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19821530 ◽

1982 ◽

Vol 47 (5) ◽

pp. 1530-1536 ◽

Cited By ~ 1

Author(s):

Ladislav Bilisics ◽

Štefan Karácsonyi ◽

Marta Kubačková

Keyword(s):

Tissue Culture ◽

Cell Walls ◽

Enzyme Preparation ◽

Uridine Diphosphate ◽

Populus Alba ◽

Activity Change ◽

White Poplar ◽

Culture Cells ◽

Tissue Culture Cells ◽

Galactose Content

The presence of UDP-D-glucose 4-epimerase (EC 5.1.3.2) in the culture tissue of white poplar was evidenced. As found, the partially purified enzyme preparation contained UDP-D-glucose glucosyltransferase, UDP-D-galactose galactosyltransferase and non-specific enzymes able to cleave the uridine-diphosphate saccharides into the appropriate hexose monophosphates. The activity change of UDP-D-glucose 4-epimerase in tissue culture cells during the growth was in accord with changes in D-galactose content in cell walls and indicated the possibility to regulate the formation of polysaccharides containing D-galactose at the level of production of UDP-D-galactose in cells.

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