Glutathione, function

Glutaric acid, structure of, 753 Glutathione, function of. 668 prostaglandin biosynthesis and, 1070... 

Although it is primarily an intracellular compound, glutathione is secreted by epithelial and other cells. It may regulate the redox state of proteins in plasma and other extracellular fluids as well as within cells. In addition, glutathione released from the liver may be an important source of cysteine for other tissues. In the endoplasmic reticulum and the periplasm of bacteria glutathione functions in crosslinking thiol groups in newly formed proteins (Eq. 10-9). 

Becker, K., Rahlfs, S., Nickel, C., and Schirmer, R. H. (2003b). Glutathione-functions and metabolism in the malarial parasite Plasmodium falciparum. Biol. Chem. 384,551-566. 

Biochemical Connections List two ways in which glutathione functions in red blood cells. 

Chai, R, Wang, C.,et al. Colorimetric detection of Pb2+ using glutathione functionalized goldnanoparticles. ACSApphed Materials Interfaces,2(5), 1466-1470 (2010). 

Another enzymatic reaction in which glutathione functions as a coenzyme in a manner similar to the glyoxalase reaction described above,... 

The source of the methyl group is S-adenosylmethionine. Glutathione functions as a reducing agent and undergoes reversible oxidative coupling to a disulfide. 

Acetaminophen, which depletes hepatic glutathione, does not potentiate the toxicity of methyl parathion in mice. A possible mechanism of action may be competition between acetaminophen and methyl parathion for mixed function oxidases and subsequent prevention of activation of methyl parathion to methyl paraoxon (Costa and Murphy 1984). Diethyl maleate, an agent that depletes cytosolic glutathione and is not an enzyme inducer, potentiates toxicity of methyl parathion in mice (Mirer et al. 1977). 

Apart from their catalytic function, at least one form of glutathione-5-trans-ferases has the function of simply binding xenobiotics and transporting them, without metabolism. In effect, this is an example of storage (see Section 2.3.3). The form in question is termed ligandin, and binding is associated with one particular subunit. Binding is not associated with catalytic activity. 

Ji X, Tordova M, O Donnell R, Parsons JF, Hayden JB, Gilliland GL, et al. Structnre and function of the xenobiotic substrate-binding site and location of a potential non-substrate-binding site in a class pi glutathione -transferase. Biochemistry 1997 36 9690-702. 

In erythrocytes, the pathway has a major function in preventing hemolysis by providing NADPH to maintain glutathione in the reduced state as the substrate for glutathione peroxidase. 

Glutathione has other important functions in human cells apart from its role in xenobiotic metabolism. 

SHEEHAN D, MEADE G, FOLEY V M and DOWD 0 A (2001) Structure, function and evolution of glutathione transferases implications for classification of non-mammalian members of an ancient enzyme superfamily , Biochem J, 360 1-16. 

It is possible that dietary flavonoids participate in the regulation of cellular function independent of their antioxidant properties. Other non-antioxidant direct effects reported include inhibition of prooxidant enzymes (xanthine oxidase, NAD(P)H oxidase, lipoxygenases), induction of antioxidant enzymes (superoxide dismutase, gluthathione peroxidase, glutathione S-transferase), and inhibition of redox-sensitive transcription factors. 

Cytochemical Analysis of Na/K Pump Function in Langendorff-perfused Isolated Hearts Effect of Glutathione... 

Influence of Glutathione Status on Sarcolemmal Protein Function... 

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