Search results for "glutathione transferase"
showing 10 items of 84 documents
Study of enzymatic activity in human neuroblastoma cells SH-SY5Y exposed to zearalenone's derivates and beauvericin.
2021
Abstract Beauvericin (BEA), α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL), are produced by several Fusarium species that contaminate cereal grains. These mycotoxins can cause cytotoxicity and neurotoxicity in various cell lines and they are also capable of produce oxidative stress at molecular level. However, mammalian cells are equipped with a protective endogenous antioxidant system formed by no-enzymatic antioxidant and enzymatic protective systems such as glutathione peroxidase (GPx), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD). The aim of this study was evaluating the effects of α-ZEL, β-ZEL and BEA, on enzymatic GPx, GST, CAT and SOD activity in huma…
Detoxication of carcinogenic fjord-region diol epoxides of polycyclic aromatic hydrocarbons by glutathione transferase P1-1 variants and glutathione.
1998
AbstractEpidemiological studies suggest that individuals differing in the expression of allelic variants of the human glutathione transferase (GST) Pi gene differ in susceptibility to chemical carcinogens such as polycyclic aromatic hydrocarbons (PAH). This study reports the catalytic efficiencies (kcat/Km) of two naturally occurring variants, GSTP1-1/I-105 and GSTP1-1/V-105, towards a series of fjord-region diol epoxides representing potent biologically active PAH metabolites, and two GSTP1-1 mutants with Ala105 and Trp105 in the active site. The results indicate that individuals who are homozygous for the allele encoding GSTP1-1/V-105 might be more susceptible to PAH carcinogenesis due to…
Differential Enantioselectivity of Murine GlutathioneS-Transferase Isoenzymes in the Glutathione Conjugation ofTrans-3,4-dihydroxy-1,2-oxy- 1,2,3,4-t…
1998
Abstract The kinetics of the glutathione (GSH) conjugation of (+)- and (−)-enantiomers ofanti- as well assyn-3,4-dihydroxy-1,2-oxy-1,2,3,4-tetrahydrobenzo[c]phenanthrene (B[c]PDE) catalyzed by murine GSHS-transferase (GST) isoenzymes has been investigated. Murine GSTs exhibited significant differences in their enantioselectivity toward B[c]PDE stereoisomers. For example, while pi class isoenzyme mGSTP1-1 was virtually inactive toward stereoisomers with 1Sconfiguration [(−)-syn-and (+)-anti-B[c]PDE], these stereoisomers were good substrates for alpha class isoenzyme mGSTA1-2. When GST activity was measured as a function of varying B[c]PDE concentration (10–320 μM) at a fixed saturating conce…
Dependency of the in vitro stabilization of differentiated functions in liver parenchymal cells on the type of cell line used for co-culture.
1992
The differentiation status in cultures of primary rat liver parenchymal cells was determined by measuring the activities of various xenobiotic metabolizing enzymes. Most enzyme activities dropped rather rapidly in monocultures of parenchymal cells. The protein content and the activities of cytosolic epoxide hydrolase, glutathione S-transferase, and alpha-naphthol UDP-glucuronosyl transferase were, however, well stabilized in 7-day-old co-cultures of parenchymal cells with two different lines of rat liver nonparenchymal epithelial cells (NEC1 and NEC2). Phenol sulfotransferase and microsomal epoxide hydrolase activity were reduced in this coculture system after 7 days to about 30 and 20% of …
Oxidative DNA damage and disturbance of antioxidant capacity by alternariol in Caco-2 cells
2015
Oxidative stress occurs as a consequence of an imbalance between the prooxidant/antioxidant systems, causing an increase of intracellular generation of reactive oxygen species. Alternariol (AOH), a mycotoxin produced by Alternaria sp. can alter the action of glutathione (GSH) and the enzymes involved in the redox system, causing damage to cellular macromolecules such as DNA. The aims of this work were to determine the induction of oxidative stress by the antioxidant defenses imbalance in relation to glutathione (GSH), glutathione reductase (GR), glutathione transferase (GST), glutathione peroxidase (GPx) levels and DNA damage in Caco-2 cells derived from adenocarcinoma human colon. Oxidativ…
Binding of PTEN to specific PDZ domains contributes to PTEN protein stability and phosphorylation by microtubule-associated serine/threonine kinases
2005
The tumor suppressor phosphatase PTEN is a key regulator of cell growth and apoptosis that interacts with PDZ domains from regulatory proteins, including MAGI-1/2/3, hDlg, and MAST205. Here we identified novel PTEN-binding PDZ domains within the MAST205-related proteins, syntrophin-associated serine/threonine kinase and MAST3, characterized the regions of PTEN involved in its interaction with distinctive PDZ domains, and analyzed the functional consequences on PTEN of PDZ domain binding. Using a panel of PTEN mutations, as well as PTEN chimeras containing distinct domains of the related protein TPTE, we found that the PTP and C2 domains of PTEN do not affect PDZ domain binding and that the …
When the nose must remain responsive: glutathione conjugation of the mammary pheromone in the newborn rabbit
2014
In insects, xenobiotic-metabolizing enzymes were demonstrated to regulate pheromones inactivation, clearing them from the olfactory periphery and keeping receptors ready for stimulation renewal. Here, we investigate whether similar processes could occur in mammals, focusing on the pheromonal communication between female rabbits and their newborns. Lactating rabbits emit in their milk a volatile aldehyde, 2-methylbut-2-enal, that elicits searching-grasping in neonates; called the mammary pheromone (MP), it is critical for pups which are constrained to find nipples within the 5 min of daily nursing. For newborns, it is thus essential to remain sensitive to this odorant during the whole nursin…
Sterigmatocystin-induced cytotoxicity via oxidative stress induction in human neuroblastoma cells.
2020
Abstract Sterigmatocystin (STE) is a mycotoxin produced by fungi of the genus Aspergillus. Considering that the effect of STE on neuronal system has not been well studied, the aim of the present study consists to investigate the cytotoxic effects of STE in human neuroblastoma (SH-SY5Y) cells. Moreover, the role of oxidative stress and intracellular defense systems was assessed by evaluating reactive oxygen species (ROS) generation, lipid peroxidation (LPO) and antioxidant no-enzymatic (GSH) levels and enzymatic (GPx, GST, CAT and SOD) activity. Our results revealed that STE decreased cell viability in a dose and time-dependent manner. Furthermore, after 24 h of exposure, STE induced an incr…
Domains of the E1 Protein of Human Papillomavirus Type 33 Involved in Binding to the E2 Protein
1996
Papillomavirus E1 and E2 proteins are essential for the initiation of viral DNA replication. We have now analyzed the interaction of E1 and E2 of human papillomavirus type 33, which is associated with cervical carcinoma. When synthesized in insect cells using the baculovirus expression system, the E1 and E2 proteins interacted efficiently at 4 degree. A monoclonal antibody recognizing E1 amino acids 584--600 inhibited the binding of E2 and vice versa, indicating that these amino acids are involved in E2 binding. To confirm this result, a mutational analysis of E1 was performed. The E2 binding activity of E1 deletion and point mutant proteins was assayed using glutathione S-transferase E1 fu…
The effect of two sulphur-containing pesticides, fenitrothion and endosulfan, on glutathione (GSH) content and on GSH S-transferase and gamma-glutamy…
1988
The glutathione (GSH) system of Procambarus clarkii (P.c.), the American red crayfish, is used as a marker of the effects of Fenitrothion (FT) and Endosulfan (ES), organophosphorus and organochlorinated insecticides, respectively. This system has been shown to be sensitive to different heavy metals poisoning, thus it has a double interest as marker for environmental contamination and as a potential source of xenobiotics or their metabolites to humans, since it is being fished commercially. The GSH content of the organ decreased 24 h after treatment with FT. FT promotes a 2-fold induction of GSH S-transferase (GST) activity at 6 h which is followed by a decrease of it at 24 h. The latter coi…