Investigation on the interaction of acid phosphatase with putrescine using docking, simulations methods and multispectroscopic techniques

The effect of putrescine on the dynamics, conformation, and kinetics of acid phosphatase investigated via different experimental and theoretical methods. The Stern-Volmer constants (K-sv) for the acid phosphatase- putrescine compound was obtained at different temperatures. Therefore, putrescine quenched the intensity of the enzyme via the static method. Gibbs free energy displayed which binding process was spontaneous. MD simulation, docking method, and thermodynamic parameters revealed the van der Waals forces and hydrogen bonding that had the specific interaction in unfolding the compound. After putrescine binding, the V-max amounts of acid phosphatase without changed, and the value of k(cat)/K-m increased. The T-m the acid phosphatase-putrescine compound was decreased. Presumably because of more surface hydrophilicity and further H-bond formation underlying the putrescine modification. As confirmed by fluorescence spectra and UV-Visible spectroscopy. Circular dichroism (CD) and UV absorption investigations also demonstrated which binding of putrescine to acid phosphatase led to microenvironmental variations around the protein. Therefore, putrescine cause changes in its structure and function. The results, therefore, showed the effect of putrescine was because of its kosmotropic specifications. Molecular dynamics simulation and Molecular docking results further confirmed the results obtained by CD and spectroscopy experiments. (C) 2020 Published by Elsevier B.V.