The interaction of xylitol with carboxypeptidase A: The influence of xylitol on enzyme structure and activity

Abstract

The influence of xylitol on the conformational stability, structure, and activity of bovine pancreas carboxypeptidase A was evaluated with UV–Vis spectroscopy, spectrofluorimetry, circular dichroism (CD), and kinetic studies, as well as molecular docking. It was discovered that xylitol suppressed carboxypeptidase A's intrinsic fluorescence in the static mode by monitoring the fluorescence peaks at two temperatures (308 and 318 K). Furthermore, calculations of thermodynamic parameters revealed that the xylitol binds spontaneously to carboxypeptidase A, and van der Waals' interaction with hydrogen bonds play an essential role in the stabilization of carboxypeptidase A. The molecular docking calculations confirmed quenching fluorescence results. Furthermore, CD spectrums and fluorescence data suggested that xylitol affected the structure of carboxypeptidase A. The melting temperature (Tm) for carboxypeptidase A increased as the xylitol concentration increased, following the thermal stability tests for carboxypeptidase A xylitol complex. Furthermore, kinetic investigations revealed that xylitol raised the Vmax and kcat/Km values, implying that xylitol treated carboxypeptidase A is more stable and active than free enzyme.