An Investigation Of The Interaction Between Urea And Valine Dipeptide Based On ABEEM/MM Method

Yang et al. have constructed a new fluctuating charge force field,i.e. the atom-bond electronegativity equalization method fused into molecular mechenics (ABEEM/MM), which has received broad attention recently. This method can describe the molecular electrostatic polarization as the environment changed, which conforms to the requirements of the development of a new generation of polarized force field.In this thesis, we applied ABEEM/MM to investigate the interaction of urea and valine peptide. The structures of 18 conformations of the urea and valine peptide complex were obtained, as well as the molecular interaction energies and charge distributions. The results obtained from our model agree well with those of ab initio method,and this indicates of the rationality of the theoretical model and the reasonableness of parameters of ABEEM/MM.Evident charge tranfer is found, after the interaction of urea and valine peptide, especially on the atoms of forming hydrogen bonds. The binding energies of the 18 conformations are different in virtue of forming different kinds of hydrogen bonds. Results show that the stability of the complex correlates closely with the type and quantity of the hydrogen bonds. The more hydrogen bonds are, the more stable the system is, and the cyclic system is most stable.