Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.5.1.18 (glutathione S-transferase)
 22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A glutathione S-transferase from Escherichia coli has been purified approximately 800-fold with an 11% activity yield by passage through DEAE Sephacel and glutathione-agarose affinity columns. Its functional form is a homodimer of two 24,000 Da polypeptides that catalyzes the binding of glutathione and 1-chloro-2,4-dinitrobenzene with Km values of 0.25 and 1.5 mM, respectively. Optima of pH and temperature were 7.5 and 35 degrees C. The activity was stimulated (30%) by ethylenediaminetetraacetic acid. The N-terminal amino acid sequence was: Met-Leu-Leu-Phe-Ile-Leu-Pro-Gly-Ala.
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PMID:Purification and study of a bacterial glutathione S-transferase. 218 38

The primary structure of glutathione S-transferase (GST) pi from a single human placenta was determined. The structure was established by chemical characterization of tryptic and cyanogen bromide peptides as well as automated sequence analysis of the intact enzyme. The structural analysis indicated that the protein is comprised of 209 amino acid residues and gave no evidence of post-translational modifications. The amino acid sequence differed from that of the deduced amino acid sequence determined by nucleotide sequence analysis of a cDNA clone (Kano, T., Sakai, M., and Muramatsu, M., 1987, Cancer Res. 47, 5626-5630) at position 104 which contained both valine and isoleucine whereas the deduced sequence from nucleotide sequence analysis identified only isoleucine at this position. These results demonstrated that in the one individual placenta studied at least two GST pi genes are coexpressed, probably as a result of allelomorphism. Computer assisted consensus sequence evaluation identified a hydrophobic region in GST pi (residues 155-181) that was predicted to be either a buried transmembrane helical region or a signal sequence region. The significance of this hydrophobic region was interpreted in relation to the mode of action of the enzyme especially in regard to the potential involvement of a histidine in the active site mechanism. A comparison of the chemical similarity of five known human GST complete enzyme structures, one of pi, one of mu, two of alpha, and one microsomal, gave evidence that all five enzymes have evolved by a divergent evolutionary process after gene duplication, with the microsomal enzyme representing the most divergent form.
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PMID:Primary and secondary structural analyses of glutathione S-transferase pi from human placenta. 232 95

A mouse glutathione S-transferase gene encoding the Ya subunit was isolated and sequenced. The gene spans about 11 kb, contains seven exons, and encodes an mRNA of 841 nucleotides. Promoter elements, TATA and CAAT box sequences, were located 32 and 70 nucleotides upstream from the initiation of transcription site. The mRNA coding sequences of the mouse gene were highly homologous to a rat liver Ya mRNA species detected by cDNA cloning. The mouse Ya gene produces a 223-amino-acid polypeptide that differs from the 222-amino-acid rat Ya by 10 amino acid substitutions and a carboxyl terminus Phe-Lys-Ile-Gln instead of Phe-Lys-Phe. A genomic clone containing the last three exons of the rat Ya gene was also isolated, sequenced, and compared with the mouse Ya gene. An extensive sequence conservation (70-80%) in the 50 to 200 bases of introns at the exon-intron junctions as well as in the region beyond the cleavage-polyadenylation site of pre-mRNA was observed.
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PMID:Mouse glutathione S-transferase Ya subunit: gene structure and sequence. 365 5

The molecular interactions of the Src homology 2 (SH2) domain and the N-terminal proline-rich sequence motifs (pro-1 to pro-5) of the SH2 protein Shb with other components were presently characterised. Using a degenerate phosphopeptide library the preferred binding site for the Shb SH2 domain was determined to pTyr-Thr/Val/Ile-X-Leu at positions +1 to +3 relative the phosphotyrosine residue. Experiments with competing peptides and platelet-derived growth factor (PDGF) beta-receptor mutants with Y to F substitutions in autophosphorylation sites revealed multiple binding sites for the Shb SH2 domain in the receptor. The Shb SH2 domain also binds to in vitro phosphorylated fibroblast growth factor receptor-1 (FGFR-1) mainly through position Y776. The receptor experiments suggest that other residues besides the +1 to +3 positions may also be of significance for Shb binding. The pro-4/pro-5 motif of Shb binds in vitro particularly well to the Src, p85 alpha PI3-kinase and Eps8 SH3 domains expressed as GST fusion proteins. However, the GST-SH3 domain fusion proteins tested bind in vitro to peptides corresponding to the pro-1 to pro-5 motifs of Shb with low affinity and selectivity, suggesting that sequences outside the core proline motif may also be important for Shb-SH3 domain interactions. In vivo association between Shb-SH3 domain proteins v-Src and Eps8 was detected by coimmunoprecipitation. PDGF treatment did not affect the association between Eps8 and Shb. The data suggest that Shb is an adaptor protein linking SH3 domain proteins to tyrosine kinases or other tyrosine phosphorylated proteins.
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PMID:Molecular interactions of the Src homology 2 domain protein Shb with phosphotyrosine residues, tyrosine kinase receptors and Src homology 3 domain proteins. 753 62

The C-terminal region of rat glutathione S-transferase P (GST-P) was deleted by either carboxypeptidase (CPase) A and B or site-specific truncation to evaluate the role of the region in the catalytic mechanism. The C-terminal sequence from the 201st to 209th amino-acid residues is Arg-Pro-Ile-Asn-Gly-Asn-Gly-Lys-Gln. When seven of the C-terminal amino-acid residues from the C-terminus were removed by the CPases, the catalytic activity decreased in parallel with the amino-acid removal, amounting to less than 5% of that of the wild-type GST-P. On the other hand, a decrease of the catalytic activity was observed in a different manner when the C-terminal sequence was site-specifically truncated. The VmaxGSH/KmGSH values of the mutants withthree (GSTd207-209), four (GSTd206-209) and seven (GSTd203-209) C-terminal amino-acid residues deleted, were comparable or similar to that of the wild-type GST-P, whereas those of five (GSTd205-209), six (GSTd204-209), and eight (GSTd202-209) amino-acid residue-truncated mutants decreased to 43%, 40%, and 19% of that of the wild-type GST-P, respectively. Similar results were obtained as for VmaxCDNB/KmCDNB. The nine amino-acid residue-truncated mutant showed no catalytic activity. Heat treatment at 50 degrees C for 5 min had little effect on the catalytic activities of the wild-type GST-P and GSTd204-209, whereas those of GSTd207-209, GSTd206-209, GSTd203-209 and GSTd202-209 decreased to 22%, 27%, 18% and 10%, respectively, compared to the catalytic activity of the non-treated enzymes. Considering these results, it is concluded that the C-terminal region, Arg201-Gln209, has an important role in stabilizing the active-site conformation.
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PMID:The C-terminal region, Arg201-Gln209, of glutathione S-transferase P contributes to stability of the active-site conformation. 757 28

Polycyclic aromatic hydrocarbons, possible human breast carcinogens, are metabolized by cytochrome P4501A1 (CYP1A1) and glutathione S-transferase (GSTM1). A CYP1A1 polymorphism (isoleucine to valine substitution in exon 7) or the null allele for GSTM1 may affect the mutagenic potential of polycyclic aromatic hydrocarbons. We examined polymorphisms in GSTM1 and CYP1A1 in relation to breast cancer risk. Included were 216 postmenopausal Caucasian women with incident breast cancer and 282 community controls. DNA analyses suggested no increased breast cancer risk with the null GSTM1 genotype [odds ratio (OR) = 1.10; CI, 0.73-1.64], although there was some indication that the null genotype was associated with risk among the youngest postmenopausal women (OR = 2.44; CI, 0.89-6.64). Slightly elevated risk was associated with the CYP1A1 polymorphism (OR = 1.61; CI, 0.94-2.75) and was highest for those who smoked up to 29 pack-years (OR = 5.22; CI, 1.16-23.56). Statistical power to detect an effect may be limited by small numbers, and larger sample sizes would be required to corroborate these suggestive findings.
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PMID:Cytochrome P4501A1 and glutathione S-transferase (M1) genetic polymorphisms and postmenopausal breast cancer risk. 762 50

Genetically based differences in metabolism, related to MspI restriction site and Ile-Val polymorphisms of the cytochrome P450 (CYP) 1A1 gene and the null genotype of glutathione transferase class mu (GSTM1), have been reported to be associated with lung cancer susceptibility. The present study was set up to establish the frequencies of the polymorphic genotypes of CYP1A1 and GSTM1 in Sweden, to evaluate a possible increased incidence of the genotypes associated with higher lung cancer risks among Swedish lung cancer patients and to try to make a combined risk estimate for carriers of multiple risk alleles. In a healthy control group, all under 66 years of age, 53% (174/329) of the subjects were of the GSTM1(-) genotype, while in a hospital control group 49% (39/79) carried the GSTM1(-) genotype. In the investigated lung cancer patients this genotype was found in 56% (165/296) and among those patients diagnosed before 66 years of age the deficient genotype was found in 60% (78/131). The highest proportion of the GSTM1(-) genotype was found in patients diagnosed with adenocarcinoma (63%, 29/46) and small cell carcinoma (72%, 21/29) before 66 years of age and among female squamous cell carcinoma patients (79%, 15/19). The allelic variants in CYP1A1 were equally distributed in lung cancer patients and controls. The m1/m2 and m2/m2 genotypes of the MspI site and the Ile/Val genotype were, however, slightly over-represented in squamous cell carcinoma patients. Among patients with squamous cell carcinoma diagnosed before 66 years of age the m1/m2 genotype was found in 28% (10/36), whereas the same genotype was observed in 16% (52/329) of healthy control subjects. A combined risk of squamous cell carcinoma was indicated for patients, diagnosed before 66 years of age, carrying both GSTM1(-) and m2 alleles (OR = 3.0, 95% CI = 1.2-7.2).
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PMID:Genetic susceptibility to lung cancer with special emphasis on CYP1A1 and GSTM1: a study on host factors in relation to age at onset, gender and histological cancer types. 792 70

Previously, we have reported the molecular cloning of ara genes encoding a small GTP-binding protein from Arabidopsis thaliana. The criterion based on amino acid sequences suggest that such an ara gene family can be classified to be of the YPT/rab type. To examine the biochemical properties of ARA proteins, several deletions and point mutations were introduced into ara cDNAs. Mutant proteins were expressed in E. coli as GST-chimeric molecules and analyzed in terms of their GTP-binding or GTP-hydrolysing ability in vitro. The results indicate that four conserved amino acid sequence regions of ARA proteins are necessary for GTP-binding. A point mutation of Asn at position 72 for ARA-2, or 71 for ARA-4, to Ile decreased GTP-binding and a point mutation of Gln at position 126 for ARA-2, or 125 for ARA-4, to Leu suppressed GTP-hydrolysis activity. Furthermore, certain factors associated with the membrane fraction accelerated GTPase activities of ARA proteins, suggesting the presence of GTPase activating protein(s) (GAP(s)) in the vesicular transport system of higher plant cells.
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PMID:In vitro mutation analysis of Arabidopsis thaliana small GTP-binding proteins and detection of GAP-like activities in plant cells. 801 29

A close correlation between cigarette smoking associated lung cancer incidence and an Msp I restriction fragment length polymorphism (RFLP) of the human P-450 1A1 (CYP1A1) gene was found in a Japanese population in terms of genotype frequency and cigarette dose. A Val/Ile codon difference in the primary structure of the CYP1A1 protein (Val-, Ile-type) was in linkage disequilibrium with the Msp I RFLP. A synergistic increase in susceptibility to lung cancer was found when combining genotyping of CYP1A1 and the Mu-class of glutathione S-transferase (GST1). Interindividual variability in the genetic make-up of carcinogen metabolizing enzymes may thus be a key host factor to explain the differences in susceptibility to chemical carcinogenesis among individuals.
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PMID:The CYP1A1 gene and cancer susceptibility. 810 89

The p53 tumor-suppressor protein has previously been shown to bind double-stranded and single-stranded DNA. We report that the p53 protein can bind single-stranded DNA ends and catalyze DNA renaturation and DNA strand transfer. Both a bacterially expressed wild-type p53 protein and a glutathione S-transferase-wild-type p53 fusion protein catalyzed renaturation of different short (25- to 76-nt) complementary single-stranded DNA fragments and promoted strand transfer between short (36-bp) duplex DNA and complementary single-stranded DNA. Mutant p53 fusion proteins carrying amino acid substitutions Glu-213, Ile-237, or Tyr-238, derived from mutant p53 genes of Burkitt lymphomas, failed to catalyze these reactions. Wild-type p53 had significantly higher binding affinity for short (36- to 76-nt) than for longer (> or = 462-nt) single-stranded DNA fragments in an electrophoretic mobility-shift assay. Moreover, electron microscopy showed that p53 preferentially binds single-stranded DNA ends. Binding of DNA ends to p53 oligomers may allow alignment of complementary strands. These findings suggest that p53 may play a direct role in the repair of DNA breaks, including the joining of complementary single-stranded DNA ends.
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PMID:p53 binds single-stranded DNA ends and catalyzes DNA renaturation and strand transfer. 827 2


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