关键词: 手性, 赖氨酸, 密度泛函理论, 过渡态, 微扰理论, Gibbs自由能

Abstract:

We studied the chiral transition mechanism of lysine molecules and the catalysis of water molecules and hydroxyl radicals on the hydrogen transfer reaction based on amino as proton transfer bridge by using the B3LYP methods of density functional theory and the MP2 methods of perturbation theory. The results show that there are two channels a, b in the chiral transition reaction of lysine. The channel a is the dominant reaction channel, where the Gibbs free energy barrier of naked reaction of rate determining step is 252.6 kJ/mol. Besides, the chain composed of two water molecules and the chain composed of
 hydroxyl radicals and water molecules have a better catalysis in hydrogen migration, which make the free energy barrier be reduced to 1195 kJ/mol and 98.5 kJ/mol respectively. So the water molecules and hydroxyl radicals have good catalysis on the hydrogen transfer in lysine molecules and  this is the main reasons of leading to the heterogeneous of Llysine that there is hydroxyl radical in life body.

Key words: chiral, lysine, density functional theory, transition state； perturbation theory, Gibbs free energy