摘要
The bio-mimic reactions of N-phosphoryl amino acids are very important in the study of many biochemical processes. The difference of reactivity between a-COOH and b-COOH in phosphoryl aspartic acid was studied by theoretical study (Hartree-Fock and Density Functional methods) in this paper. The intermediates II containing five-membered ring were more stable than III with six-membered ring. While for intermediates III, the isomers with six-membered ring in apical-equatorial spanning arrangement were more stable than those with di-equatorial spanning arrangement. At B3LYP/6-31G** level, it was shown that transition states IV and V involving a-COOH or b-COOH group had energy barriers of DE = 58.67 kJmol-1 and 103.94 kJmol-1, respectively. These results were in agreement with the experimental data. So the a-COOH group was involved in form of the intramolecular penta-coordinate phosphoric-carboxylic mixed anhydride intermediates, but not b-COOH group.
The bio-mimic reactions of N-phosphoryl amino acids are very important in the study of many biochemical processes. The difference of reactivity between a-COOH and b-COOH in phosphoryl aspartic acid was studied by theoretical study (Hartree-Fock and Density Functional methods) in this paper. The intermediates II containing five-membered ring were more stable than III with six-membered ring. While for intermediates III, the isomers with six-membered ring in apical-equatorial spanning arrangement were more stable than those with di-equatorial spanning arrangement. At B3LYP/6-31G** level, it was shown that transition states IV and V involving a-COOH or b-COOH group had energy barriers of DE = 58.67 kJmol-1 and 103.94 kJmol-1, respectively. These results were in agreement with the experimental data. So the a-COOH group was involved in form of the intramolecular penta-coordinate phosphoric-carboxylic mixed anhydride intermediates, but not b-COOH group.
基金
the National Natural Science Foundation of China (No. 29802006)
the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE
P.R.C. and Tsinghua University.
