scholarly journals Oestrogen Sulfotransferase: Isolation of a High Specific Activity Species from Bovine Placenta

1988 ◽  
Vol 41 (3) ◽  
pp. 333 ◽  
Author(s):  
Stephen S Moore ◽  
EOP Thompson ◽  
Allan R Nash
Keyword(s):  
Mammary Cancer ◽  
Specific Activity ◽  
High Specific Activity ◽  
Gel Permeation Chromatography ◽  
Salt Precipitation ◽  
Bovine Placenta ◽  
Steroid Binding Proteins ◽  
Specific Activities ◽  
Steroid Binding ◽  
Control Of Expression

During the course of a study of the control of expression of steroid-binding proteins in human mammary cancer oestrogen sulfotransferase was isolated from bovine placenta. By a combination of salt precipitation and ion-exchange and gel-permeation chromatography two forms of the enzyme were isolated. The forms, which apparently differ only in charge, have specific activities 100-300 times greater than has previously been reported for the enzyme. Partial peptide sequences of these enzymes are presented.

scholarly journals A subclass of glutathione S-transferases as intracellular high-capacity and high-affinity steroid-binding proteins

1986 ◽  
Vol 235 (3) ◽  
pp. 763-768 ◽  
Author(s):  
H Homma ◽  
H Maruyama ◽  
Y Niitsu ◽  
I Listowsky
Keyword(s):  
Binding Capacity ◽  
High Capacity ◽  
Gel Permeation Chromatography ◽  
Hormone Metabolism ◽  
High Affinity ◽  
Glutathione S Transferases ◽  
Steroid Binding Proteins ◽  
Steroid Binding ◽  
Binding Component

The distribution of glucocorticoids incubated with rat liver cytosol preparations or administered in vivo to adrenalectomized rats was analysed by chromatographic procedures. Corticosterone or dexamethasone was co-eluted with Yb-type GSH S-transferases in anion-exchange and gel-permeation chromatography systems, and these glucocorticoids also were bound to Yb forms in analyses by immunoadsorbent and lysyl-GSH affinity matrices. Pretreatment of cytosol with lysyl-GSH to extract GSH S-transferases or incubation with excess bilirubin, which is expected to compete with steroids for binding to the protein, yielded preparations that were devoid of this major steroid-binding component. In mixtures of the multiple rat GSH S-transferases, corticosterone preferentially interacted with Yb forms rather than Ya and Yc subgroups. All of the multiple Yb forms resolved by chromatofocusing procedures retained the steroid-binding capacity. It is suggested that these abundant proteins can account for a considerable share of intracellular glucocorticoid binding and represent a high-affinity non-saturable binding component with potential to function in steroid-hormone metabolism and action.

STUDIES ON THE RELATIONSHIP BETWEEN VIRUS AND HOST CELL: THE PREPARATION OF T2r+ BACTERIOPHAGE LABELLED WITH RADIOACTIVE PHOSPHORUS

1950 ◽  
Vol 28e (6) ◽  
pp. 281-288 ◽  
Author(s):  
S. M. Lesley ◽  
R. C. French ◽  
A. F. Graham
Keyword(s):  
Nucleic Acid ◽  
Host Cell ◽  
Inorganic Phosphate ◽  
Specific Activity ◽  
High Specific Activity ◽  
Inorganic Phosphorus ◽  
Radioactive Phosphorus ◽  
Specific Activities ◽  
The Relationship ◽  
Escherichia Coli B

T2r+ bacteriophage grown in its host, Escherichia coli B, in broth medium in the presence of radioactive inorganic phosphorus was labelled with the isotope. Purified suspensions of this virus had specific activities up to 50,000 c.p.m. per μgm. P. There was little or no exchange of P32 between virus and inorganic phosphate. Chemical analysis showed that at least 98% of the virus phosphorus was contained in nucleic acid; of the nucleic acid phosphorus 95.5% was associated with desoxypentose nucleic acid and 4.5% with pentose nucleic acid. More than 99% of the radioactivity of the labelled bacteriophage was contained in the nucleic acid fraction. Preparations of bacteriophage were obtained with sufficiently high specific activity to enable metabolism experiments to be carried out on the growth of the labelled virus in the host cell.

Eine Methode zur Darstellung Tritium-markierter cancerogener polycyclischer Kohlenwasserstoffe mit extrem hoher spezifischer Aktivität

1966 ◽  
Vol 21 (9) ◽  
pp. 855-858 ◽  
Author(s):  
Hans Emmerich ◽  
Peter Schmialek
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Thin Layer ◽  
Paper Chromatography ◽  
Aromatic Hydrocarbons ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
High Specific Activity ◽  
Polycyclic Aromatic ◽  
Specific Activities

A method is described for the preparation of tritiated polycyclic aromatic hydrocarbons with extremely high specific activity in the presence of AlCl3 and HTO. The hydrocarbons are purified by preparative thin layer and paper chromatography. The radiochemical purity of the compounds was proved by paper chromatography and dilution analysis. The following specific activities are reached: Anthracene: 54 Curies/mMol, 7,12-Dimethylbenzanthracene: 19 Curies/mMol, 3,4-Benzopyrene: 24 Curies/mMol, and 3-Methylcholanthrene: 44 Curies/mMol.

scholarly journals Preparation of 125I-thyioxine and 125I-triiodothyronine of High Specific Activity for the Radioimmunoassay of Serum Total T4 and T3

1976 ◽  
Vol 13 (1-6) ◽  
pp. 364-368 ◽  
Author(s):  
Vanessa R. Thurlow ◽  
Hilary J. Puxley
Keyword(s):  
Shelf Life ◽  
Specific Activity ◽  
High Specific Activity ◽  
Specific Activities ◽  
Inexpensive Procedure

A simple and inexpensive procedure for the preparation of high specific activity 125I radioiodinated triiodothyronine and thyroxine is described. The specific activities achieved are approximately 350 Ci/g for 125I-T4, and either 220 Ci/g or 500 Ci/g for 125I-T3 depending on the reagents employed. The high specific activity 125I-T4 and 125I-T3 are suitable for the routine radioimmunoassay of serum total T3 and T4. When properly stored they have a shelf life of at least seven weeks.

scholarly journals STREPTOCOCCAL NUCLEASES

1967 ◽  
Vol 126 (3) ◽  
pp. 497-508 ◽  
Author(s):  
Lewis W. Wannamaker ◽  
Barbara Hayes ◽  
Walid Yasmineh
Keyword(s):  
Ribonucleic Acid ◽  
Specific Activity ◽  
High Specific Activity ◽  
The Other ◽  
Acid Inhibitor ◽  
Bacterial Rna ◽  
Zone Electrophoresis ◽  
Specific Activities ◽  
And Behavior ◽  
Deoxyribonuclease Activity

Preparations of streptococcal DNAse D with high specific activity and free of other streptococcal nucleases have been obtained by zone electrophoresis and column chromatography. Antisera prepared by injecting rabbits with such preparations specifically neutralize the activity of this enzyme. As with DNAse B, preparations of DNAse D regularly exhibit ribonuclease activity. For both B and D enzymes, the order of substrate preference is thymus DNA, yeast RNA, bacterial RNA; but the specific activity of the D enzyme is higher than that of the B enzyme with respect to thymus DNA and lower with respect to bacterial RNA. Both the deoxyribonuclease and the ribonuclease activities exhibited by preparations of both enzymes are inhibited by bacterial RNA, but approximately 100-fold greater concentrations of bacterial RNA are required to achieve inhibition of the deoxyribonuclease activity of the D enzyme equivalent to the inhibition of the B enzyme. The deoxyribonuclease activity of the D enzyme is also inhibited by yeast RNA, but even larger amounts are required. These observations indicate that the D enzyme is immunologically distinct from the other streptococcal nucleases and that it differs quantitatively from the B enzyme with respect to relative specific activities on different substrates and behavior in the presence of the bacterial ribonucleic acid inhibitor.

An International Collaborative Study to Investigate Standardisation of Hirudin Potency

1993 ◽  
Vol 69 (05) ◽  
pp. 430-435 ◽  
Author(s):  
Colin Longstaff ◽  
Man-Yu Wong ◽  
Patrick J Gaffney
Keyword(s):  
Specific Activity ◽  
Collaborative Study ◽  
Residual Activity ◽  
Quality Standard ◽  
Upper Limit ◽  
Assay Procedure ◽  
Specific Activities ◽  
International Collaborative ◽  
Range Of Values ◽  
International Collaborative Study

SummaryAn international collaborative study has been carried out to investigate the reproducibility of hirudin assays in 13 laboratories using four recombinant hirudins and one natural, sulphated product. A simple assay procedure was proposed involving the titration of α-thrombin with inhibitor and measurement of residual activity using a chromogenic substrate. A standard α-thrombin preparation was supplied to ensure that this reagent was of uniform quality throughout the study. The method appeared to present no difficulties and laboratories reported similar potencies for the 5 hirudin samples, in line with expected values. This gave 200–222 Thrombin Inhibitory Units/ampoule (TIU/ampoule) of lyophilised hirudin, with geometric coefficient of variation (gcv) values ranging from 10.15–15.97%. This corresponds to specific activities of approximately 14,300–15,900 TIU/mg protein. This is close to the upper limit of previously reported values of specific activity. We conclude that the precision of this determination compared with the wider range of values in the literature (8,000–16,000 thrombin inhibitory units [TIU]/mg) results from the use of good quality standard α-thrombin by all laboratories. This study has important implications for hirudin standardisation.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

Autoprothrombin C Activity from Prothrombin with Snake Venom or Trypsin

1962 ◽  
Vol 08 (03) ◽  
pp. 425-433 ◽  
Author(s):  
Ewa Marciniak ◽  
Edmond R Cole ◽  
Walter H Seegers
Keyword(s):  
Snake Venom ◽  
Thrombolytic Agent ◽  
Sodium Citrate ◽  
Specific Activity ◽  
High Specific Activity ◽  
Citrate Solution ◽  
Clotting Factors ◽  
Activation Products ◽  
Russell’S Viper ◽  
Autoprothrombin C

SummarySuitable conditions were found for the generation of autoprothrombin C from purified prothrombin with the use of Russell’s viper venom or trypsin. DEAE chromatographed prothrombin is structurally altered and has never been found to yield autoprothrombin C and also did not yield it when Russell’s viper venom or trypsin were used. Autoprothrombin C is derived from prothrombin with tissue extract thromboplastin, but not in large amounts with the intrinsic clotting factors. With the latter thrombin and autoprothrombin III are the chief activation products. Autoprothrombin III concentrates were prepared from serum and upon activation with 25% sodium citrate solution or with Russell’s viper venom large amounts of autoprothrombin C were obtained, and this was of high specific activity. Theoretically trypsin is not a thrombolytic agent, but on the contrary should lead to intravascular clotting.

MEASUREMENT OF STEROID BINDING PROTEINS

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S104-S121 ◽  
Author(s):  
E. E. Baulieu ◽  
J. P. Raynaud ◽  
E. Milgrom
Keyword(s):  
Kinetic Parameters ◽  
Binding Proteins ◽  
Binding Specificity ◽  
Binding Parameters ◽  
Target Organs ◽  
Biological Mixtures ◽  
Steroid Binding Proteins ◽  
Steroid Binding ◽  
Steroid Binding Protein

ABSTRACT A brief review of the characteristics of steroid binding proteins found in the plasma and in some target organs is presented, followed by some general remarks on binding »specificity« and binding parameters. Useful techniques for measuring binding parameters at equilibrium are reported, both those which keep the equilibrium intact and those which implicate its disruption. A concept is developed according to which the determination of a specific steroid binding protein is based on the »differential dissociation« of the several steroid binding complexes present in most biological mixtures. Methods which allow determination of the kinetic parameters of the binding systems are also presented. Various representations of the binding and therefore different modes of graphic representation and calculation are discussed, including the recent »proportion graph« method.

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