scholarly journals Relative contributions of thioltransferase-and thioredoxin-dependent systems in reduction of low-molecular-mass and protein disulphides

1983 ◽  
Vol 213 (2) ◽  
pp. 519-523 ◽  
Author(s):  
B Mannervik ◽  
K Axelsson ◽  
A C Sundewall ◽  
A Holmgren
Keyword(s):  
Small Molecules ◽  
Reduced Glutathione ◽  
Relative Effectiveness ◽  
Thioredoxin Reductase ◽  
Liver Cytosol ◽  
Enzyme Systems ◽  
Bovine Trypsin ◽  
Disulphide Bonds ◽  
Thioredoxin System ◽  
Rat Liver Cytosol

Two enzyme systems capable of reducing disulphide bonds both in low-Mr compounds and in polypeptides and proteins exist. One consists of thioltransferase in combination with reduced glutathione and glutathione reductase, and the second consists of thioredoxin in combination with thioredoxin reductase. Their relative effectiveness in catalysing disulphide reduction of various substrates in rat liver cytosol was evaluated in the present study. The thioltransferase-dependent system was found to be more efficient in reducing small molecules. Insulin was most effectively reduced by the thioredoxin system. Bovine trypsin was a better substrate for thioltransferase, and partially proteolysed bovine serum albumin was equally good for the two systems. Thus, in the case of protein disulphide bonds, the nature of the particular substrate used determines which of the two reducing systems is the more important.

Bacterial and mammalian thioredoxin systems activate iodothyronine 5′-deiodination

1988 ◽  
Vol 66 (5) ◽  
pp. 460-464 ◽  
Author(s):  
Arun K. Das ◽  
Brian C. W. Hummel ◽  
Florence K. Gleason ◽  
Arne Holmgren ◽  
Paul G. Walfish
Keyword(s):  
Escherichia Coli ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Thioredoxin Reductase ◽  
Relative Mass ◽  
Rat Liver Microsomes ◽  
Liver Cytosol ◽  
E Coli ◽  
Thioredoxin System ◽  
Rat Liver Cytosol

The identity of a dithiol (designated DFB) of relative mass (Mr) = 13 000, reported previously to be present infraction B of rat liver cytosol and to participate as a cofactor in the 5′-deiodination of iodothyronines, has been investigated. Substitution of highly purified thioredoxin from Escherichia coli for fraction B or of highly purified thioredoxin reductase from either E. coli or rat liver for cytosolic fraction A (containing DFB reductase) permits deiodination of 3,3′,5′-[l25I]triiodothyronine by rat liver microsomes to proceed. Addition of antibodies to highly purified rat-liver thioredoxin or thioredoxin reductase inhibits deiodination. Thus, the thioredoxin system largely accounts for the activity of the cytosolic cofactor system supporting 5′-deiodination of 3,3′,5′-triiodothyronine in rat liver.

scholarly journals Reduction of disulphide bonds in proteins mixed disulphides catalysed by a thioltransferase in rat liver cytosol

1975 ◽  
Vol 149 (3) ◽  
pp. 785-788 ◽  
Author(s):  
B Mannervik ◽  
K Axelsson
Keyword(s):  
Glutathione Reductase ◽  
Rat Liver ◽  
Direct Reduction ◽  
Liver Cytosol ◽  
Disulphide Bonds ◽  
Enzymic Reaction ◽  
Spontaneous Reaction ◽  
Rat Liver Cytosol

The reduction of mixed disulphides of some proteins and GSH [Protein(-SSG)n] is accomplished with GSH as a reductant and a thioltransferase from rat liver as a catalyst, thus: See article. The spontaneous reaction is negligible in comparison with the enzymic reaction in vivo, and any direct reduction with glutathione reductase is not detectable with the substrates used. The reduction is only indirectly dependent on NADPH, which is required for the regeneration of GSH from GSSG. Other protein disulphides apparently are reduced via analogous GSH-dependent reactions

scholarly journals Cholic acid binding by glutathione S-transferases from rat liver cytosol

1980 ◽  
Vol 185 (1) ◽  
pp. 83-87 ◽  
Author(s):  
J D Hayes ◽  
R C Strange ◽  
I W Percy-Robb
Keyword(s):  
Bile Acid ◽  
Cholic Acid ◽  
Reduced Glutathione ◽  
Binding Activity ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Liver Cytosol ◽  
Glutathione S Transferases ◽  
Rat Livers ◽  
Rat Liver Cytosol

Cholic acid-binding activity in cytosol from rat livers appears to be mainly associated with enzymes having glutathione S-transferase activity; at least four of the enzymes in this group can bind the bile acid. Examination of the subunit compositions of different glutathione S-transferases indicated that cholic acid binding and the ability to conjugate reduced glutathione with 1,2-dichloro-4-nitrobenzene may be ascribed to different subunits.

scholarly journals Alterations in translatable messenger RNA coding for phosphoenolpyruvate carboxykinase (GTP) in rat liver cytosol during deinduction.

1978 ◽  
Vol 253 (12) ◽  
pp. 4327-4332
Author(s):  
D. Kioussis ◽  
L. Reshef ◽  
H. Cohen ◽  
S.M. Tilghman ◽  
P.B. Iynedjian ◽  
...  
Keyword(s):  
Rat Liver ◽  
Messenger Rna ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Liver Cytosol ◽  
Rat Liver Cytosol

scholarly journals Transformation of the glucocorticoid receptor in rat liver cytosol by lysosomal enzymes.

1979 ◽  
Vol 254 (5) ◽  
pp. 1537-1539 ◽  
Author(s):  
J. Carlstedt-Duke ◽  
O. Wrange ◽  
E. Dahlberg ◽  
J.A. Gustafsson ◽  
B. Högberg
Keyword(s):  
Glucocorticoid Receptor ◽  
Rat Liver ◽  
Lysosomal Enzymes ◽  
Liver Cytosol ◽  
Rat Liver Cytosol

Development of an [3H] glucocorticoid exchange assay in rat liver cytosol

Steroids ◽  
1981 ◽  
Vol 37 (4) ◽  
pp. 409-421 ◽  
Author(s):  
Ashutosh Banerji ◽  
Mohammed Kalimi
Keyword(s):  
Rat Liver ◽  
Liver Cytosol ◽  
Rat Liver Cytosol
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