Theoretical study of hydrogen transfer process for some amino acids

초록

Our previous research showed that the PAULING cavity model is the best choice in dealing with the glycine chemistry in aqueous solution. Although the activation energy barrier for intra-molecular hydrogen transfer process was more or less comparable to experimental value, the side chain in amino acids would affect the activation barrier. In this work, we investigated the effect of side chains on the hydrogen transfer process for some amino acids. In aqueous solution, the two NE conformers and ZW conformer were fully optimized at the CPCM-B3LYP/6-311+G(d,p) level adopting PAULING cavity model. All calculations were performed by using the Gaussian 03 program. The NE and ZW structures were verified as minima with no imaginary frequency and as a transition state with only one imaginary frequency, respectively.