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)

The hypolipidemic drug clofibrate is known to affect the hepatic transport of various organic anions including bilirubin, fatty acids and sulfobromophthalein. Changes in the rate of metabolism and/or intracellular transport have been claimed responsible for the effect. To evaluate these possibilities, the transport of sulfobromophthalein-glutathione, a model compound that does not require metabolism for biliary excretion, was studied in perfused livers isolated from clofibrate-treated and control rats. Cytosolic fatty acid binding protein and glutathione S-transferase activity were also measured. Clofibrate treatment significantly increased liver weight; as a result glutathione S-transferase activity (toward 1-chloro-2,4-dinitrobenzene) fell if expressed per gram of liver (4560 +/- 420 (SE) vs 7010 +/- 260 nmoles/min for clofibrate treated and controls respectively, p less than 0.002), but was unchanged when expressed per total liver (60.8 +/- 6.5 vs 64.6 +/- 3.5 mumoles/min for clofibrate and controls p greater than 0.5). Irrespective of how it was expressed fatty acid binding protein was significantly increased by the drug treatment. Steady state sulfobromophthalein-glutathione removal velocity was saturable with increasing concentrations of sulfobromophthalein-glutathione in both control and clofibrate-treated livers. Steady state extraction ratio, as well as Vmax and Km for removal, did not differ between the two groups. In keeping with other observations, these data collectively indicate that the hepatic steady state removal of nonmetabolized compounds is not affected by clofibrate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The hepatocellular transport of sulfobromophthalein-glutathione by clofibrate treated, perfused rat liver. 275 20

Organic anions can be excreted from the liver into the bile or back into the general circulation (sinusoidal efflux). It has previously been shown that the net sinusoidal efflux rate of dibromosulfophthalein from the perfused liver into the perfusate is the result of actual efflux from and reuptake into the liver, and can be strongly influenced by the presence of bovine serum albumin in the perfusion medium. The present study investigated whether the influence of albumin on the net sinusoidal efflux process is albumin-specific or whether other binding proteins could have a similar effect on the sinusoidal efflux. Using a single-pass liver perfusion technique and short-lasting (pulse) protein infusions, the stimulatory effect of a wide range of dibromosulfophthalein binding proteins on the sinusoidal efflux process were determined. These experiments showed that all the serum albumins tested as well as the liver cytosolic binding proteins fatty acid binding protein and ligandin (glutathione S-transferase) stimulated this process. The other proteins tested, bovine beta lactoglobulin-b, human gamma globulin and chicken egg lysozyme showed no stimulatory effect, despite relatively high equilibrium binding of dibromosulfophthalein. No clear-cut relationship was found between the equilibrium unbound ligand concentration as measured in perfusate and the stimulatory effect, suggesting absence of equilibrium binding in the sinusoids. Equilibrium binding of dibromosulfophthalein to chicken serum albumin and ligandin as well as the dissociation rate constants were determined in vitro with rapid filtration techniques.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The sinusoidal efflux of dibromosulfophthalein from rat liver is stimulated by albumin, ligandin and fatty acid binding protein but not by other dibromosulfophthalein binding proteins. 752 96

Multifocal recurrent papillary tumors provide a unique model system to study the molecular mechanisms underlying the steps involved in transitional cell carcinoma progression and offer a valuable source of material to search for biomarkers that may form the basis for diagnosis, prognosis, and treatment. We have examined the protein expression profiles of normal bladder urothelium and of 63 transitional cell carcinomas of various histopathological grades and T stages using high-resolution, two-dimensional gel electrophoresis, microsequencing, mass spectrometry, and a two-dimensional gel protein database approach for polypeptide identification (http://biobase.dk/cgi-bin/celis). In general, the results revealed a striking similarity between the overall qualitative expression patterns of papillary tumors of all grades, as well as of papillary and solid tumors of grade III. With few exceptions, tumors of grades I-III expressed, albeit at different levels, all of the keratins (7, 8, 13, 17, 18, 19, and 20) found in the normal urothelium. Grade IV tumors lacked or expressed reduced levels of keratin 13 but most resembled low-grade tumors. One invasive grade IV tumor, however, expressed a fibroblast-like protein phenotype. Four proteins that were expressed by normal urothelium and were lost at various stages of progression were identified as glutathione S-transferase mu, prostaglandin dehydrogenase (PGDH), a fatty acid binding protein with homology to the adipocyte isoform (A-FABP), and keratin 13. The percentage of tumors expressing A-FABP was very high in low-grade lesions but decreased drastically (P = 0.0006) in grade III and IV neoplasms. In addition, low-grade tumors contained more A-FABP than their high-grade counterparts. The stage of the disease was also statistically (P = 0.0269) related to the presence or absence of A-FABP in grade III tumors. Similar analysis of glutathione S-transferase mu and PGDH showed a statistically significant decrease of these proteins in high-grade (grades III and IV) tumors (P = 0.0026 and P = 0.0044, respectively). Only PGDH showed a suggestive correlation (P = 0.0775) with the stage of the disease in grade III tumors. Keratin 13 showed a drastic decrease in grade IV tumors. In addition to identifying biomarkers that may have prognostic value, our studies have suggested that A-FABP is an important component of the pathway(s) leading to bladder cancer development.
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PMID:Loss of adipocyte-type fatty acid binding protein and other protein biomarkers is associated with progression of human bladder transitional cell carcinomas. 884 Sep 99

The immunological relationship between liver flukes and their mammalian hosts is being unravelled by in vivo and in vitro studies. Vaccine studies in cattle and sheep with purified antigens (fatty acid binding protein, FABP; glutathione S-transferase, GST; cathepsin L, CatL; hemoglobin) have shown that high reductions in worm burdens (31-72%) and egg production (69-98%) can be achieved, raising the realistic possibility that immunological control of Fasciola infection is a commercially achievable goal. Combination vaccines may also be feasible since a cocktail of CatL and hemoglobin elicits a significant 72% protection in cattle. Analysis of immune responses to Fasciola during infection in ruminants suggests that chronic infection correlates with a type 2 helper T cell response, implying that type 1 helper T cell responses are down-regulated in fasciolosis. Recent results studying the resistance of Indonesian Thin Tail (ITT) sheep to F. gigantica have shown that this breed exhibits high innate (or rapidly acquired) resistance to infection and acquires a higher level of resistance after a primary challenge. Initial studies suggest that the resistance of ITT sheep to F. gigantica may be determined by a major gene. Merino sheep also acquire resistance to F. gigantica. In contrast, ITT and Merino sheep do not exhibit resistance to F. hepatica. These results suggest that there are fundamental differences between these two species of Fasciola in the biology of their interaction with the sheep immune system. In vitro studies on immune mechanisms of killing of juvenile fluke have shown that juvenile larvae of F. hepatica are susceptible to antibody-dependent killing by activated rat macrophages in vitro which is mediated by nitric oxide. Future studies on the immune effector mechanisms expressed by resistant sheep which control infection by F. gigantica will lead to new knowledge which may allow the design of more effective vaccines for fasciolosis.
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PMID:Immunological approaches for the control of fasciolosis. 939 93

Vaccine trials were conducted in Brahman cross cattle evaluating the efficacy of 4 native antigens purified from adult Fasciola gigantica flukes, and 1 recombinant F. gigantica antigen, as vaccines against tropical fasciolosis. The antigens tested were native glutathione S-transferase, cathepsin L, paramyosin, fatty acid binding protein (FABP), and a recombinant FABP expressed in E. coli, and were formulated in 1 or more of several adjuvants (Quil A, Squalene Montanide 80, MF59-100, Auspharm, NAGO, polylactoglycolide microspheres, Algammulin, DEAE, Freund's). Vaccination induced low, moderate or high antibody titres to the various antigens which were dependent on the adjuvant. Low but significant reductions in fluke burdens (31%, P < 0.026) and fluke wet weight (36%, P < 0.041) were only observed in cattle vaccinated with the native FABP in Freund's adjuvant. There was no correlation between total antibody titres to FABP and protection. The protection observed in cattle vaccinated with native FABP of F. gigantica supports the notion that this class of proteins is a useful target for protection of animals against Fasciola and extends the efficacy of FABPs to the tropical liver fluke. This is the first report of vaccination of cattle against F. gigantica with a purified protein.
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PMID:Evaluation of antigens of Fasciola gigantica as vaccines against tropical fasciolosis in cattle. 942 34

This review discusses some of the recent advances in the characterization of potential vaccine molecules against Schistosoma japonicum, utilizing microscopy and immunocytochemistry methods. Microscopy has demonstrated the stage-specific expression of the muscle protein paramyosin onto the parasite surface, an important consideration as a vaccine target. Other potential vaccine component proteins examined include glutathione S-transferase (GST) and fatty acid binding protein (FABP); although not associated with the adult parasite surface, their localization to internal structures such as lipid droplets and regions of the female reproductive system have provided valuable insights into the biology of the parasite. Localization of the transport protein SGTP (schistosome glucose transporter protein) has demonstrated that the protein is more prevalent in the juvenile stages of the parasite development. This further highlights the diversity of the parasite life cycle. Using both light microscopy and transmission electron microscopy, the localization of a number of schistosome proteins has demonstrated the functions and significance of these proteins within the parasite. Molecular localization studies are crucial in understanding how and when a vaccine may work against the organism and may provide insights into which can be used in the design of future vaccines.
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PMID:Immunolocalization of schistosome proteins. 976 18

The hepatotoxicity of bromobenzene and many other simple organic chemicals is believed to be associated with covalent binding of chemically reactive metabolites to cellular proteins. Recently, a rat liver microsomal esterase was shown to be targeted by bromobenzene metabolites formed in vitro [Rombach, E. M., and Hanzlik, R. P. (1998) Chem. Res. Toxicol. 11, 178-184]. To identify protein targets for bromobenzene metabolites in cytosol, we incubated liver microsomes and glutathione-depleted liver cytosol from phenobarbital-treated rats with [(14)C]bromobenzene in vitro. In a separate experiment, we intraperitoneally injected a hepatotoxic dose of [(14)C]bromobenzene to phenobarbital-treated rats. The cytosol fractions from both experiments were recovered and analyzed for protein-bound radioactivity. Under the conditions that were used, 2.6 and 3.9 nmolar equiv of bromobenzene/mg of cytosolic protein was bound in vitro and in vivo, respectively. Denaturing polyacrylamide gel electrophoresis of these cytosolic proteins followed by phosphor imaging analysis revealed several radiolabeled protein bands over a broad molecular mass range, the patterns observed in vitro and in vivo being generally similar to each other. Cytosolic proteins labeled in vitro were separated by ion exchange chromatography and electrophoresis, and three major radioactive bands with estimated molecular masses of ca. 14, 25, and 30 kDa were in-gel digested with trypsin, followed by on-line HPLC electrospray ionization mass spectrometry of the resulting peptide mixtures. For the three protein bands, the observed peptide masses were found to match the predicted tryptic fragments of liver fatty acid binding protein, glutathione transferase subunit A1, and carbonic anhydrase isoform III, respectively, with 83, 45, and 59% coverage of the corresponding complete sequences. The possible relationship of the adduction of these proteins to the toxicological outcome is discussed.
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PMID:Identification of three protein targets for reactive metabolites of bromobenzene in rat liver cytosol. 1112 75

A 600 bp DNA fragment was amplified by PCR, from an adult Schistosoma japonicum cDNA library. Sequence analysis revealed that this fragment containedthe S. japonicum Chinese Mainland strain fatty acid binding protein (Sj-14FABPc) gene. This gene was then cloned into the expression vector pGEX-2T, and subsequently expressed in Escherichia coli. The recombinant GST-fusion protein could be purified by glutathione agarose affinity chromatography. Its molecular weight was about 41 kD. The yield of expression was around 25 mg/L E. coli culture. The immunological test suggested that the recombinant protein had good antigenicity, and could be developed into a new vaccine molecule of S. japonicum.
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PMID:Cloning of Schistosoma japonicum Chinese Strain Fatty Acid Binding Protein (Sj-FABPc) Gene and Its Overproduction in Escherichia coli. 1217 84

Disposition kinetics of [(3)H]palmitate and its low-molecular-weight metabolites in perfused rat livers were studied using the multiple-indicator dilution technique, a selective assay for [(3)H]palmitate and its low-molecular-weight metabolites, and several physiologically based pharmacokinetic models. The level of liver fatty acid binding protein (L-FABP), other intrahepatic binding proteins (microsomal protein, albumin, and glutathione S-transferase) and the outflow profiles of [(3)H]palmitate and metabolites were measured in four experimental groups of rats: 1) males; 2) clofibrate-treated males; 3) females; and 4) pregnant females. A slow-diffusion/bound model was found to better describe the hepatic disposition of unchanged [(3)H]palmitate than other pharmacokinetic models. The L-FABP levels followed the order: pregnant female > clofibrate-treated male > female > male. Levels of other intrahepatic proteins did not differ significantly. The hepatic extraction ratio and mean transit time for unchanged palmitate, as well as the production of low-molecular-weight metabolites of palmitate and their retention in the liver, increased with increasing L-FABP levels. Palmitate metabolic clearance, permeability-surface area product, retention of palmitate by the liver, and cytoplasmic diffusion constant for unchanged [(3)H]palmitate also increased with increasing L-FABP levels. It is concluded that the variability in hepatic pharmacokinetics of unchanged [(3)H]palmitate and its low-molecular-weight metabolites in perfused rat livers is related to levels of L-FABP and not those of other intrahepatic proteins.
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PMID:Fatty acid binding protein is a major determinant of hepatic pharmacokinetics of palmitate and its metabolites. 1244 13

Here, we describe a proteomics approach to study protein expression changes in differentiating Caco-2 cells. Caco-2 is a colorectal carcinoma cell line, which upon differentiation loses its tumorigenic phenotype and displays characteristics of mature enterocytes, including brush borders with microvilli. Cells were grown in culture flasks and harvested at different stages of differentiation (days post-confluence: -3, 0, 3, 7, 10, 14, and 18). Two-dimensional gel electrophoresis was used to analyse proteome changes. Approximately 1400 protein spots were detected within the Caco-2 proteome, within the pH 4-7 range. Two-dimensional gel electrophoresis allowed for the detection of 18 proteins from which the levels of expression were found to be associated with differentiation. Of these proteins, 11 were identified by means of MALDI-TOF or NANO-ESI-MS/MS mass spectrometry and include liver fatty acid binding protein (FABL), three forms of alpha-enolase (ENOA), nucleoside diphosphate kinase A (NDKA), cofilin-1 (COF1), translationally controlled tumour protein (TCTP), mitochondrial 60-kDa heat shock protein (CH60), probable protein disulfide isomerase (ER60), creatine kinase B (KCRB), and glutathione S-transferase alpha (GTA1). Thus, proteomics revealed that the differentiation-related change in phenotype of Caco-2 involves changes in a variety of distinct biochemical pathways. Some of these proteins have not been shown before to be associated with Caco-2 differentiation (ER60; COF1; CH60; NDKA; TCTP and ENOA). Therefore, processes related to protein folding and disulfide bridge formation, cytoskeleton formation and maintenance, nucleotide metabolism, glycolysis as well as tumorigenesis-associated proteins may be involved in Caco-2 differentiation. Changes in the expression of CH60, TCTP, GTA1, NDKA, and FABL have also been reported to be associated with in vivo colon carcinogenesis. These findings illustrate that a combination of proteomics and cell culture is a useful approach to find markers for Caco-2 differentiation, which could contribute to the comprehension of the process of colon carcinogenesis.
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PMID:Proteome analysis reveals novel proteins associated with proliferation and differentiation of the colorectal cancer cell line Caco-2. 1292 71


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