Possible Interaction: Melatonin and Tyrosine

“The substitution of the hydrophobic residues Phe126, Ile128 and Phe178 by tyrosines at the active site significantly increased enzymatic activity and decreased the affinity of a structural analog of melatonin , the 2[(125)I]iodo-MCANAT.”

“ Tyrosine concentration increased during 30 days from melatonin treatment (12.79 ± 3.93 vs 27.08 ± 3.04 AU) but at 90 days its levels were similar to the untreated group.”

“Preincubation of mitochondrial proteins from wild‐type mice with melatonin prevented 3‐tyrosine nitration of these proteins, eliminated the reduction in the MRC activity, the defect in the assembly of mitochondrial complexes and degradation of their subunits induced by peroxynitrite in vitro.”

“Furthermore, melatonin partially reversed the CA‐induced phosphorylation of the catalytic subunit of PP‐2A at tyrosine 307 , a crucial site that negatively regulates the activity of PP‐2A, and reduced the levels of malondialdehyde and the activity of superoxide dismutase, which are markers of oxidative stress.”

“In this study, using immunoprecipitation and immunoblotting, we show that melatonin induces rapid tyrosine phosphorylation and activation of the insulin receptor β‐subunit tyrosine kinase (IR) in the rat hypothalamic suprachiasmatic region.”

“The results indicate that melatonin stimulation generates tyrosine phosphorylation of a high molecular weight protein, an event that seems to be essential for melanosome aggregation.”

“It was suggested that 5-methoxytryptamine, melatonin and alpha-lipoic acid reacted only with the nitrating intermediate of peroxynitrite and inhibited nitration of L-tyrosine.”