Possible Interaction: Adenosine Triphosphate and Tryptophan

“ ATP induces a decrease in the polarity of the membrane, increases the number of ANS binding sites, and the quantum yield per site, and induces a blue shift of the membrane tryptophan intrinsic fluorescence.”

“The results of protein pathway analysis showed that L-Trp stimulated glycolysis, the pentose phosphate pathway, and ATP synthesis, which are pathways involved in energy metabolism.”

“mRNA encoding tryptophan hydroxylase 1 was detected in the urinary bladder by nested RT-PCR amplification, and l-tryptophan or the selective serotonin reuptake inhibitor citalopram also inhibited ATP release, indicating that 5-HT is endogenously synthesized and released in the urinary bladder.”

“ TRP was opened by DAG and silenced by ATP , suggesting DAG-kinase (DGK) involvement.”

“Replacement of Phe(475) with Trp and Glu(446) with Gln profoundly reduced the binding of ATP , whereas the substitution of Ser(445) with Ala did not affect ATP binding.”

“These findings suggest that ATP moderately changes the microenvironment of one or more tryptophan or tyrosine residues in holoGAD and alters these residues from a more mobile state to a less mobile one.”

“The lifetime data allow us to conclude that the environment of the buried tryptophans becomes more flexible upon the binding of ATP , while the other ligands did not induce such change.”

“The tryptophan residues involved respond to the binding of ATP at the hydrolytic sites.”

“Binding of ATP and l-tryptophan together is synergistic, the Kd-values being decreased by two thirds.”

“The bound tryptophan can react stoichiometrically with ATP to give tryptophanyladenylate which remains bound to the enzyme.”