Possible Interaction: Proline and Tryptophan

“ Tryptophan at 0.50% reduced total HCAs the most (0.92 ng/g, 93% inhibition), followed by 0.50% lysine (1.94 ng/g, 84% inhibition), while leucine (3.95 ng/g, 64% inhibition) and proline (4.71 ng/g, 56% inhibition) were less effective at 0.50%.”

“Glycine, l-alanine, and l-tryptophan strongly inhibited l-proline uptake indicating that these amino acids also interact with the transport system.”

“Although neither 5-hydroxy-l-tryptophan nor α-methyl-d l-tryptophan were able to elicit inward current in PAT2-expressing oocytes both reduced the current evoked by l-proline.”

“ l-Proline uptake was inhibited by 5-hydroxy-l-tryptophan (IC50 1.6 ± 0.4 mM), α-methyl-d, l-tryptophan (3.5 ± 1.5 mM), l-tryptophan, 1-methyl-l-tryptophan and indole-3-propionic acid.”

“Certain other amino acids (L-valine, L-alanine, L-methionine, L-phenylalanine, L-tryptophan and L-hydroxyproline) significantly stimulated proline uptake.”

“Glycine, lysine, arginine, valine, isoleucine, and tryptophan in the second position are (with N-terminal serine) strongly inhibitory, and proline completely blocks modification.”

“A mixture of L‐pro and L‐tryptophan ( L‐trp ) at lower concentrations of each yielded increased inhibition, compared with the findings when each inhibitor was tested by itself.”

“ PRO acted as a stabilizer for the co-amorphous system, including NAP– TRP , through enhancing the molecular interactions in the form of hydrogen bonds between all three components in the mixture.”