Nucleic Acid Bases Pyrimidine To Form Complexes With Calcium And Magnesium Ions

Experimental methods of cluster studying are summarized and a series of quantum theories used in the study of cluster are explicit discussed. By using laser ablation technique, the complexes of metal cation (Ca~+) -RNA nucleic acid pyramiding bases are gained and studied by time-flight mass spectra in gas phase. Theoretical studies of the interaction between calcium and magnesium univalent and divalent captions and nucleic acid pyramiding bases are choused to be the main work of this academic dissertation. The information gained is interesting because it can help people to know the interaction between nucleic acid and calcium and magnesium captions and administer people to understand how calcium and magnesium captions influence the process of biochemical action and probably assist people to find out how calcium and magnesium univalent actions turns into its divalent cations in some respects.A density functional investigation of the interaction between calcium and magnesium univalent cations and nucleic acid pyrimidine bases is performed at Becke' s three-parameter functional with Perdew-Wang correlational functional (B3LYP)/6-311+G (2df, 2p) level to determine coordination geometries, stabilities, absolute metal ion affinities and vibrational frequencies for all possible complexation stable products. Cations are allowed to interact with the canonical and noncanonical tautomers of free bases after a careful selection of several attachment sites. By comparing of the total energies of the dissimilar structures, there are some differences in the congeneric complexes; According to ions affinities, magnesium univalent shows a greater affinity for nucleic acid bases than calcium univalent ;In term of the stale stuctures, cations engage with oxygen and nitrogen. All complexes are characterized by a ionic interaction between ligand and metal ions that appears slightly more pronounced for magnesium.Further more, frequency jobs for all stable comp lexes, which is composed of calcium and magnesium bivalent cations and...