Simulation of the effect of water on the electronic structure of tyrosine by dipoles

Abstract

It is necessary to construct a simple, easy-to-use equivalent potential of water for the electronic structure of protein in order to calculate the electronic structures of proteins in solution more reliably. The first-principles, all-electron, ab initio calculations have been performed to simulate the effect of water on the electronic structure of tyrosine (Tyr). The process involved three steps: firstly, search for the minimum-energy configuration of the system Tyr+7H2O; secondly, calculate the electronic structure of Tyr with the potential of water molecules via the self-consistent cluster-embedding (SCCE) method; finally, simulate the effect of water on Tyr by dipoles. The results show that the major effect of water on the electronic structure of Tyr is to lower the eigenvalues of two orbitals by about 0.0158 Ry on average, and to raise the other six eigenvalues by about 0.0302 Ry on average. The effect of water on the electronic structure of Tyr can be well simulated by dipoles.