A Comparison of the Enzymatic and Physicochemical Properties of Human Glutathione Transferase M4-4 and Three Other Human Mu Class Enzymes

Comstock, Kenine E.; Widersten, Mikael; Hao, Xiao-Yong; Henner, W. David; Mannervik, Bengt

doi:10.1006/abbi.1994.1266

Cited by 63 publications

(40 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Specific activities with EA and 4-HNE substrates were determined spectrophotometrically in 0.1 M sodium phosphate at pH 6.2 based on reported molar extinction coefficients of the products (34,35). The initial concentrations of substrates were 0.1 mM EA and 1.0 mM GSH, or 0.05 mM 4-HNE and 0.5 mM GSH.…”

Section: Methodsmentioning

confidence: 99%

The Enhanced Affinity for Thiolate Anion and Activation of Enzyme-bound Glutathione Is Governed by an Arginine Residue of Human Mu Class Glutathione S-Transferases

Patskovsky

Patskovska

Listowsky

2000

Journal of Biological Chemistry

View full text Add to dashboard Cite

A series of chimeric human Mu class glutathione Stransferases were designed to determine mechanisms by which they activate enzyme-bound glutathione (GSH) for reaction with electrophilic substrates. and Tyr 6 residues are required for thiolate anion formation and stabilization. The three-dimensional structure of ligand-free hGSTM2-2 determined by x-ray crystallography suggests that Arg 107 maintains an electrostatic interaction with the Asp 161 side chain (3 Å apart), but is distant from the GSH-binding site. However, an alternative energetically favorable model places the guanidino group 4 Å from the sulfur atom of bound GSH. It is suggested therefore, that in solution, motion of the positively charged arginine into the catalytic pocket could provide a counter ion to promote ionization of the sulfhydryl group of GSH, thereby accounting for the observed greater affinity of enzymes containing Arg 107 for binding of thiolate anion.

show abstract

Section: Methodsmentioning

confidence: 99%

The Enhanced Affinity for Thiolate Anion and Activation of Enzyme-bound Glutathione Is Governed by an Arginine Residue of Human Mu Class Glutathione S-Transferases

Patskovsky

Patskovska

Listowsky

2000

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…GSTM4 has a high level of amino-acid sequence identity, but distinct physiochemical properties and tissue distributions, as compared with other GSTMs (Comstock et al, 1993(Comstock et al, , 1994. GSTM4 does not show comparable activity with the standard GST substrate and its specific substrates have yet to be identified.…”

Section: Formationmentioning

confidence: 99%

GSTM4 is a microsatellite-containing EWS/FLI target involved in Ewing's sarcoma oncogenesis and therapeutic resistance

et al. 2009

View full text Add to dashboard Cite

Ewing's sarcoma is a malignant bone-associated tumor of children and young adults. Most cases of Ewing's sarcoma express the EWS/FLI fusion protein. EWS/FLI functions as an aberrant ETS-type transcription factor and serves as the master regulator of Ewing's sarcoma-transformed phenotype. We recently showed that EWS/FLI regulates one of its key targets, NR0B1, through a GGAAmicrosatellite in its promoter. Whether other critical EWS/FLI targets are also regulated by GGAA-microsatellites was unknown. In this study, we combined transcriptional analysis, whole genome localization data, and RNA interference knockdown to identify glutathione S-transferase M4 (GSTM4) as a critical EWS/FLI target gene in Ewing's sarcoma. We found that EWS/FLI directly binds the GSTM4 promoter, and regulates GSTM4 expression through a GGAA-microsatellite in its promoter. Reduction of GSTM4 levels caused a loss of oncogenic transformation. Furthermore, reduction of GSTM4 resulted in an increased sensitivity of Ewing's sarcoma cells to chemotherapeutic agents, suggesting a role for this protein in drug resistance. Consistent with this hypothesis, patients with Ewing's sarcoma whose tumors had higher levels of GSTM4 expression had worse outcomes than those with lower expression levels. These data show that GSTM4 contributes to the cancerous behavior of Ewing's sarcoma and define a wider role for GGAA-microsatellites in EWS/FLI function than previously appreciated. These data also suggest a novel therapeutic resistance mechanism, in which the central oncogenic abnormality directly regulates a resistance gene.

show abstract

“…Theta-class GSTs in general have been notoriously hard to identify because they normally do not bind to affinity matrices such as GSH-agarose [1]. In addition, most lack detectable activity toward CDNB, and thus can be missed if GST activity is the only means of GST isolation [54,55]. The unique activity of theta-class GSTs can be traced to the presence of the essential Ser-11, responsible for glutathione deprotonation and activation, in place of the tyrosine found in the alpha, mu, and pi class GSTs [56].…”

Section: Discussionmentioning

confidence: 99%

Proteomic identification, cDNA cloning and enzymatic activity of glutathione S-transferases from the generalist marine gastropod, Cyphoma gibbosum

Whalen¹,

Morin²,

Lin³

et al. 2008

Archives of Biochemistry and Biophysics

View full text Add to dashboard Cite

Short title: Characterization of glutathione S-transferases from Cyphoma gibbosumFootnote: The nucleotide and translated amino acid sequences for C. gibbosum GSTs have been deposited in GenBank with the following accession nos. EU008563 (CgGSTM1) and EU008562 (CgGSTM2).Abbreviations footnote: CDNB, 1-chloro-2,4-dinitrobenzene; GST, glutathione S-transferase; nrDB, non-redundant database; RACE, rapid amplification of cDNA ends; RT-PCR, reverse transcriptase polymerase chain reaction 2 ABSTRACT Glutathione S-transferases (GST) were characterized from the digestive gland of Cyphoma gibbosum (Mollusca; Gastropoda), to investigate the possible role of these detoxification enzymes in conferring resistance to allelochemicals present in its gorgonian coral diet. We identified the collection of expressed cytosolic Cyphoma GST classes using a proteomic approach involving affinity chromatography, HPLC and nanospray liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two major GST subunits were identified as putative mu-class GSTs; while one minor GST subunit was identified as a putative theta-class GST, apparently the first theta-class GST identified from a mollusc. Two Cyphoma GST cDNAs (CgGSTM1 and CgGSTM2) were isolated by RT-PCR using primers derived from peptide sequences. Phylogenetic analyses established both cDNAs as mu-class GSTs and revealed a mollusc-specific subclass of the GST-mu clade. These results provide new insights into metazoan GST diversity and the biochemical mechanisms used by marine organisms to cope with their chemically defended prey.

show abstract

A Comparison of the Enzymatic and Physicochemical Properties of Human Glutathione Transferase M4-4 and Three Other Human Mu Class Enzymes

Cited by 63 publications

References 0 publications

The Enhanced Affinity for Thiolate Anion and Activation of Enzyme-bound Glutathione Is Governed by an Arginine Residue of Human Mu Class Glutathione S-Transferases

The Enhanced Affinity for Thiolate Anion and Activation of Enzyme-bound Glutathione Is Governed by an Arginine Residue of Human Mu Class Glutathione S-Transferases

GSTM4 is a microsatellite-containing EWS/FLI target involved in Ewing's sarcoma oncogenesis and therapeutic resistance

Proteomic identification, cDNA cloning and enzymatic activity of glutathione S-transferases from the generalist marine gastropod, Cyphoma gibbosum

Contact Info

Product

Resources

About