Probing the binding mechanisms of α-tocopherol to trypsin and pepsin using isothermal titration calorimetry, spectroscopic, and molecular modeling methods.

ABSTRACT: α-Tocopherol is a required nutrient for a variety of biological functions. In this study, the binding of α-tocopherol to trypsin and pepsin was investigated using isothermal titration calorimetry (ITC), steady-state and time-resolved fluorescence measurements, circular dichroism (CD) spectroscopy, and molecular modeling methods. Thermodynamic investigations reveal that α-tocopherol binds to trypsin/pepsin is synergistically driven by enthalpy and entropy. The fluorescence experimental results indicate that α-tocopherol can quench the fluorescence of trypsin/pepsin through a static quenching mechanism. The binding ability of α-tocopherol with trypsin/pepsin is in the intermediate range, and one molecule of α-tocopherol combines with one molecule of trypsin/pepsin. As shown by circular dichr

SUBMITTER: Li X 

PROVIDER: S-EPMC4942422 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature