Binding parameters and molecular dynamics of Trypsin-Acid Yellow 17 complexation as a function of concentration

Acid Yellow 17 is a kind of azo dye used in food, textile, and cosmetics. Several studies explain the toxicity of azo dye for our body, but one could not find further information about the effects of these dyes on human macromolecules. In the current study, the interaction of AY17 with trypsin is investigated using several techniques. The UV analysis displayed that the absorption of trypsin could be decreased in the presence of this color. The fluorescence investigation indicated that a static form of quenching happens, and a 50% decrease in the fluorescence intensity, also showed the Vander Waals and hydrogen bond are the main forces in the interaction of this color and trypsin. Furthermore, we can observe that the T_m point of trypsin decreases from 46.5 to 42. On the other hand, the CD results were indicated that the interaction of this color with trypsin could decrease the percent of turn, coil and α-helix in trypsin structure. The computational study was undertaken to obtain more information about the interaction between trypsin and AY17. The results were in agreement with the experimental investigation and indicated that the interaction between this color and trypsin leads to less compactness in the trypsin structure.