Dataset Information

Isolation of a mouse theta glutathione S-transferase active with methylene chloride.

ABSTRACT: A glutathione S-transferase metabolizing methylene chloride has been isolated from mouse liver using a variety of chromatographic methods. N-terminal and internal amino acid sequences show that the enzyme, designated GST T1-1*, is closely related to the rat Theta-class GST 5-5. The mouse enzyme, molecular mass 25000 Da, has been isolated to homogeneity in active form with an approximate yield of 2% of the cytosolic activity towards methylene chloride. GST T1-1* has a specific activity of about 5.5 micromol/min per mg of protein whereas the rat GST 5-5 is reported to have a specific activity of about 11 micromol/min per mg of protein [Meyer, Coles, Pemble, Gilmore, Fraser and Ketterer (1991) Biochem. J. 274, 409-414], demonstrating that both the rat and mouse enzymes have similar activity with this substrate. Limited evidence was obtained for a second enzyme, with a similar molecular mass (25400 Da), which had an N-terminal sequence identical to that of rat GST 12-12. This protein, which was sequenced from a band on a gel, was extremely labile and could not be isolated to homogeneity. The partially purified enzyme was not active with methylene chloride.

SUBMITTER: Mainwaring GW

PROVIDER: S-EPMC1217070 | biostudies-other | 1996 Mar

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:Chloroplasts are organelles subjected to extreme oxidative stress conditions. Biomolecules produced in the chloroplasts act as signals guiding plant metabolism toward stress tolerance and play a major role in regulating gene expression in the nucleus. Herein, we used transplastomic plants as an alternative approach to expression of transgenes in the nucleus for conferring stress tolerance to abiotic stresses and herbicides. To investigate the morphophysiological and molecular mechanisms and the role of plastid expressed GSTs in tobacco stress detoxification and stress tolerance, we used transplastomic tobacco lines overexpressing a theta class glutathione transferase (GST) in chloroplasts. The transplastomic plants were tested under drought (0, 100, and 200 mM mannitol) and salinity (0, 150, and 300 mM NaCl) in vitro, and under herbicide stress (Diquat). Our results suggest that pt AtGSTT lines were tolerant to herbicide-induced oxidative and salinity stresses and showed enhanced response tolerance to mannitol-induced osmotic stress compared to WT plants. Overexpression of the Arabidopsis thaliana AtGSTT in the chloroplasts resulted in enhanced photo-tolerance and turgor maintenance under stress. Whole-genome transcriptome analysis revealed that genes related to stress tolerance, were upregulated in pt AtGSTT2a line under both control and high mannitol stress conditions. Transplastomic plants overexpressing the pt AtGSTT2a in the chloroplast showed a state of acclimation to stress, as only limited number of genes were upregulated in the pt AtGSTT2a transplastomic line compared to WT under stress conditions while at the same time genes related to stress tolerance were upregulated in pt AtGSTT2a plants compared to WT in stress-free conditions. In parallel, the metabolic profile indicated limited perturbations of the metabolic homeostasis in the transplastomic lines and greater accumulation of mannitol, and soluble sugars under high mannitol stress. Therefore, transplastomic lines seem to be in a state of acclimation to stress under stress-free conditions, which was maintained even under high mannitol stress. The results help to elucidate the role of GSTs in plant abiotic stress tolerance and the underlying mechanisms of the GSTs expressed in the chloroplast, toward environmental resilience of cultivated crops.

Dataset Information

Isolation of a mouse theta glutathione S-transferase active with methylene chloride.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure