Study of the Interaction of Novel Nonprotein Amino Acids with Trypsin by Steady-State Fluorescence Spectroscopy.

The interaction of (2R, 3S)-hydroxyleucine (trypsin inhibitor) and β-hydroxyvaline with trypsin has been studied by the steady-state fluorescence spectroscopy. The analysis of fluorescence spectra has revealed the mechanism of binding of these nonprotein amino acids to trypsin. According to the docking (2R, 3S)-hydroxyleucine form hydrogen bonds with trypsin having little effect on tryptophan and tyrosine residues in enzyme molecule. The results obtained in this study indicate that fluorescence of trypsin is quenched at high concentrations of amino acids. Thus fluorescence spectra analysis confirms data obtained by molecular docking.