Possible Interaction: Glutathione and Tyrosine

“We observed that the inhibition caused by tyrosine was concentration-dependent and was prevented by reduced glutathione.”

“A consistent feature of the Alpha-, Mu- and Pi-class glutathione transferases (GSTs) is the presence near the N-terminus of a tyrosine residue that contributes to the activation of glutathione.”

“The increased tyrosine radicals can be reduced by endogenic antioxidants such as GSH.”

“Complete inhibition of tyrosine phosphorylation was noticed when cells were stimulated in the presence of N-acetylcysteine or glutathione.”

“GSH concentration in newly collected plasma from day … to 115 microM, while the titer of tyrosine , a substrate for the PO cascade, was 141 microM. GSH titers rapidly declined in …, but no melanin formation occurred until GSH levels fell below 20 microM. Added GSH dose-dependently blocked … GSH inhibition.”

“These results indicate that tyrosine 9 is directly responsible for the lowering of the pKa of the sulfhydryl group of glutathione , presumably due to the stabilization of the thiolate anion through hydrogen bonding with the hydroxyl group of tyrosine.”

“In contrast, Cu tyrosine causes a slight drop in GSH in starved animals.”

“ Glutathione , serotonin and synthetic sulfur- and selenium-containing compounds inhibited both the nitration and oxidation reaction of L-tyrosine effectively.”

“ Glutathione and synthetic compounds ((2S,3R,4S)-N-ethylmercapto-3,4-dihydroxy-2-hydroxymethylpyrrolidine, L-N-dithiocarboxyproline) inhibited both the nitration and the oxidation reactions of L-tyrosine effectively.”

“In addition, glutathione has been shown to activate at least one step in tyrosine oxidation , and the indications were that still another labile cofactor for which low concentrations of 2,6-dichlorophenol indophenol could substitute was involved in the system.”