A study of noncovalent interaction in dimers of amino acid with positive charge using quantum mechanics method
Noncovalent interaction exists in nature widely,especially it plays an important role during the interaction of protein and nucleic acid in organisms,which actually is the interaction between the side chain of amino acids and bases.Therefore,the accurate prediction of the interaction between the side chain of amino acids and bases is extremely important in life science.Correlated Quantum Mechanics(QM)methods are used to calculate the interaction energy of 15 dimers of amino acid with positive charge and compared with those calculated at the level of CCSD(T)/CBS.It shows that the Root Mean Squared Error(RMSE)of SCS-CCSD/CBS method is 0.06 kcal/mol,and the linear correlation coefficient is 0.999 8.The RMSE of SCS-MI-CCSD/CBS method is 0.11 kcal/mol,and the linear correlation coefficient is 0.999 9.The RMSE of MP2.5/CBS method is 0.13 kcal/mol,and the linear correlation coefficient is 0.999 3.These results prove the reliability of the correlated QM methods,and then,MP2.5/CBS method is applied to calculate the interaction energies for the stacking dimers including arginine,histidine and lysine side chains with neutral molecules at different intermolecular distances,which could be used as the benchmark value of the noncovalent interaction for positively charged stacking dimers.
noncovalent interactionquantum mechanics methodstacking dimerside chain of amino acid
万方数据
维普
