scholarly journals Glutathione S-transferases of human brain. Evidence for two immunologically distinct types of 26500-Mr subunits

1985 ◽  
Vol 225 (2) ◽  
pp. 375-382 ◽  
Author(s):  
C Theodore ◽  
S V Singh ◽  
T D Hong ◽  
Y C Awasthi

Human brain contains one cationic (pI8.3) and two anionic (pI5.5 and 4.6) forms of glutathione S-transferase. The cationic form (pI8.3) and the less-anionic form (pI5.5) do not correspond to any of the glutathione S-transferases previously characterized in human tissues. Both of these forms are dimers of 26500-Mr subunits; however, immunological and catalytic properties indicate that these two enzyme forms are different from each other. The cationic form (pI8.3) cross-reacts with antibodies raised against cationic glutathione S-transferases of human liver, whereas the anionic form (pI5.5) does not. Additionally, only the cationic form expresses glutathione peroxidase activity. The other anionic form (pI4.6) is a dimer of 24500-Mr and 22500-Mr subunits. Two-dimensional gel electrophoresis demonstrates that there are three types of 26500-Mr subunits, two types of 24500-Mr subunits and two types of 22500-Mr subunits present in the glutathione S-transferases of human brain.

1987 ◽  
Vol 244 (1) ◽  
pp. 55-61 ◽  
Author(s):  
P K Stockman ◽  
L I McLellan ◽  
J D Hayes

The basic glutathione S-transferases in human liver are composed of at least two immunochemically distinct polypeptides, designated B1 and B2. These subunits exist as homodimers, but can hybridize to form the B1B2 heterodimer [Stockman, Beckett & Hayes (1985) Biochem. J. 227, 457-465]. Although these basic glutathione S-transferases possess similar catalytic properties, the B2 subunit exhibits significantly greater selenium-independent glutathione peroxidase activity than subunit B1. The use of the ligands haematin, tributyltin acetate and Bromosulphophthalein as inhibitors of 1-chloro-2,4-dinitrobenzene-GSH-conjugating activity clearly discriminate between the B1 and B2 subunits and should help facilitate their identification. Peptide mapping experiments showed that B1 and B2 are structurally distinct, but related, subunits; subunit B1 yielded 43 tryptic peptides, seven of which were unique, whereas subunit B2 yielded 40 tryptic peptides, four of which were unique.


1984 ◽  
Vol 224 (1) ◽  
pp. 335-338 ◽  
Author(s):  
S V Singh ◽  
Y C Awasthi

Two types of 25 000-Mr subunits are present in rat lung glutathione S-transferase I (pI 8.8). These subunits, designated Yc and Yc', are immunologically and functionally distinct from each other. The homodimers YcYc (pI 10.4) and Yc'Yc' (pI 7.6) obtained by hybridization in vitro of the two subunits of glutathione S-transferase I (pI 8.8) were isolated and characterized. Results of these studies indicate that only the Yc subunits express glutathione peroxidase activity and cross-react with the antibodies raised against glutathione S-transferase B (YaYc) or rat liver. The Yc' subunits do not express glutathione peroxidase activity and do not cross-react with the antibodies raised against glutathione S-transferase B of rat liver. The amino acid compositions of these two subunits are also different. These two subunits can also be separated by the two-dimensional gel electrophoresis of glutathione S-transferase I (pI 8.8) of rat lung.


1985 ◽  
Vol 227 (2) ◽  
pp. 457-465 ◽  
Author(s):  
P K Stockman ◽  
G J Beckett ◽  
J D Hayes

The purification of a hybrid glutathione S-transferase (B1 B2) from human liver is described. This enzyme has an isoelectric point of 8.75 and the B1 and B2 subunits are distinguishable immunologically and are ionically distinct. Hybridization experiments demonstrated that B1 B1 and B2 B2 could be resolved by CM-cellulose chromatography and have pI values of 8.9 and 8.4 respectively. Transferase B1 B2, and the two homodimers from which it is formed, are electrophoretically and immunochemically distinct from the neutral enzyme (transferase mu) and two acidic enzymes (transferases rho and lambda). Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis demonstrated that B1 and B2 both have an Mr of 26 000, whereas, in contrast, transferase mu comprises subunits of Mr 27 000 and transferases rho and lambda both comprise subunits of Mr 24 500. Antisera raised against B1 or B2 monomers did not cross-react with the neutral or acidic glutathione S-transferases. The identity of transferase B1 B2 with glutathione S-transferase delta prepared by the method of Kamisaka, Habig, Ketley, Arias & Jakoby [(1975) Eur. J. Biochem. 60, 153-161] has been demonstrated, as well as its relationship to other previously described transferases.


1982 ◽  
Vol 28 (4) ◽  
pp. 782-789 ◽  
Author(s):  
D E Comings

Abstract To understand at a molecular level the basis of the normal and pathological genetic differences between individuals it is necessary to begin a detailed two-dimensional gel electrophoretic mapping of the proteins of the human brain in normal individuals and those with various genetic neurological disorders. The present study is an examination of the polypeptide patterns of extracts of the human brain made with 9 mol/L urea solution. Details of the technique and the nomenclature of the patterns obtained are presented. the gels are separated into 20 sub-sections, based on standards with known molecular masses and isoelectric points. Groups of polypeptides within these sub-sections are identified by a number and a letter; the individual proteins are identified by a number. Thus, protein 1 in subsection 8, group b, would be designated 8b: 1. Subsequent papers in this series identify many of these proteins; show which proteins belong to the cytosol, synaptosome, myelin, and other brain fractions; show how these patterns vary between normal individuals and those with different neurological and psychiatric conditions; examine the effect of severe gliosis; and present the results of non-equilibrium gel electrophoresis for the more basic proteins.


1999 ◽  
Vol 45 (3) ◽  
pp. 355-359 ◽  
Author(s):  
Theo PJ Mulder ◽  
Daniel A Court ◽  
Wilbert HM Peters

Abstract Background: Glutathione S-transferases are a family of enzymes involved in the binding, transport, and detoxification of a wide variety of endogenous and exogenous compounds. Little information is available about the variability of class α glutathione S-transferases in human liver, where they are highly expressed, or in serum. Methods: Both total class α glutathione S-transferase (GST-α, composed of GSTA1-1, GSTA1-2, and GSTA2-2) as well as GSTA1-1 concentrations were measured by specific and sensitive ELISA in liver cytosols of 35 organ donors and in plasma samples of 350 healthy controls. Results: The mean total GST-α and GSTA1-1 in liver cytosols were 25.1 ± 9.4 and 10.7 ± 5.3 μg/mg protein, respectively, and did not correlate with activities of aspartate aminotransferase or alanine aminotransferase. The mean total GST-α in liver was significantly higher in females compared with males (28.8 ± 10.0 vs 22.0 ± 7.8 μg/mg protein; P <0.05). In contrast, the median total GST-α in plasma was lower in females compared with males (2.0 and 2.8 μg/L, respectively; P <0.0001). The median ratios for GSTA1-1/total GST-α in liver and plasma were 0.42 and 0.58, respectively. Conclusions: GSTA1-1 constitutes approximately one-half of the total amount of α class GSTs in human plasma and liver. Total GST-α values are higher in female liver but lower in plasma compared with the respective values in males.


PROTEOMICS ◽  
2004 ◽  
Vol 4 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Kyla Pennington ◽  
Emma McGregor ◽  
Clare L. Beasley ◽  
Ian Everall ◽  
David Cotter ◽  
...  

1982 ◽  
Vol 28 (4) ◽  
pp. 813-818 ◽  
Author(s):  
D E Comings ◽  
A Pekkula-Flagan

Abstract To examine the basic human brain proteins, we subjected 9 mmol/L urea extracts to non-equilibrium gel electrophoresis. The pattern observed differs distinctly from that with equilibrium gel electrophoresis. With this technique, the myelin proteins (myelin basic protein, proteolipids, and basic Wolfgram proteins) and many other unindentified major basic proteins can be demonstrated. The myelin basic proteins occur as two major polypeptides of different charge and slightly different molecular mass, indicating the action of at least two genes. The proteolipid proteins occur as a long series of charge isomers, suggesting multiple genes or extensive post-transcriptional modification. In one patient with schizophrenia, a charge-change mutation of the larger myelin basic protein (MBL) was observed and is termed "MBL-Duarte."


1986 ◽  
Vol 233 (3) ◽  
pp. 779-788 ◽  
Author(s):  
J D Hayes ◽  
T J Mantle

The glutathione S-transferases are dimeric enzymes whose subunits can be defined by their mobility during sodium dodecyl sulphate/polyacrylamide-gel electrophoresis as Yf (Mr 24,500), Yk (Mr 25,000), Ya (Mr 25,500), Yn (Mr 26,500), Yb1 (Mr 27,000), Yb2 (Mr 27,000) and Yc (Mr 28,500) [Hayes (1986) Biochem. J. 233, 789-798]. Antisera were raised against each of these subunits and their specificities assessed by immuno-blotting. The transferases in extrahepatic tissues were purified by using, sequentially, S-hexylglutathione and glutathione affinity chromatography. Immune-blotting was employed to identify individual transferase polypeptides in the enzyme pools from various organs. The immuno-blots showed marked tissue-specific expression of transferase subunits. In contrast with other subunits, the Yk subunit showed poor affinity for S-hexylglutathione-Sepharose 6B in all tissues examined, and subsequent use of glutathione and glutathione affinity chromatography. Immuno-blotting was employed to identify a new cytosolic polypeptide, or polypeptides, immunochemically related to the Yk subunit but with an electrophoretic mobility similar to that of the Yc subunit; high concentrations of the new polypeptide(s) are present in colon, an organ that lacks Yc.


1983 ◽  
Vol 215 (3) ◽  
pp. 617-625 ◽  
Author(s):  
T Friedberg ◽  
U Milbert ◽  
P Bentley ◽  
T M Guenther ◽  
F Oesch

A hitherto unknown cytosolic glutathione S-transferase from rat liver was discovered and a method developed for its purification to apparent homogeneity. This enzyme had several properties that distinguished it from other glutathione S-transferases, and it was named glutathione S-transferase X. The purification procedure involved DEAE-cellulose chromatography, (NH4)2SO4 precipitation, affinity chromatography on Sepharose 4B to which glutathione was coupled and CM-cellulose chromatography, and allowed the isolation of glutathione S-transferases X, A, B and C in relatively large quantities suitable for the investigation of the toxicological role of these enzymes. Like glutathione S-transferase M, but unlike glutathione S-transferases AA, A, B, C, D and E, glutathione S-transferase X was retained on DEAE-cellulose. The end product, which was purified from rat liver 20 000 g supernatant about 50-fold, as determined with 1-chloro-2,4-dinitrobenzene as substrate and about 90-fold with the 1,2-dichloro-4-nitrobenzene as substrate, was judged to be homogeneous by several criteria, including sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, isoelectric focusing and immunoelectrophoresis. Results from sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and gel filtration indicated that transferase X was a dimer with Mr about 45 000 composed of subunits with Mr 23 500. The isoelectric point of glutathione S-transferase X was 6.9, which is different from those of most of the other glutathione S-transferases (AA, A, B and C). The amino acid composition of transferase X was similar to that of transferase C. Immunoelectrophoresis of glutathione S-transferases A, C and X and precipitation of various combinations of these antigens by antisera raised against glutathione S-transferase X or C revealed that the glutathione S-transferases A, C and X have different electrophoretic mobilities, and indicated that transferase X is immunologically similar to transferase C, less similar to transferase A and not cross-reactive to transferases B and E. In contrast with transferases B and AA, glutathione S-transferase X did not bind cholic acid, which, together with the determination of the Mr, shows that it does not possess subunits Ya or Yc. Glutathione S-transferase X did not catalyse the reaction of menaphthyl sulphate with glutathione, and was in this respect dissimilar to glutathione S-transferase M; however, it conjugated 1,2-dichloro-4-nitrobenzene very rapidly, in contrast with transferases AA, B, D and E, which were nearly inactive towards that substrate.(ABSTRACT TRUNCATED AT 400 WORDS)


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