Abstract
In Part I, we reported all-atom, fully solvated molecular dynamics (MD) simulations of epigallocatechin-3-gallate (EGCG) binding to keratin. Herein, we report the second part of experimental investigation on EGCG binding to keratin using ultrafiltration and isothermal titration calorimetry (ITC). The thermodynamic equilibrium of EGCG binding to keratin has been quantitatively determined using ultrafiltration and high-performance liquid chromatography-UV/vis. The relationship confirms multilayer binding of EGCG to keratin which was observed in MD simulations. By combining the ultrafiltration and ITC data, the thermodynamic parameters of EGCG binding to keratin have been quantified. The obtained free energy of the first layer binding (ΔG=-6.37 kcal mol) is shown in excellent agreement with that obtained from computer simulations (ΔG=-6.20 kcal mol) presented in Part I. © 2013 American Institute of Chemical Engineers.