Differentiation of alpha-COOH from beta-COOH in aspartic acids by N-phosphorylation

作者：Chen ZZ; Tan B; Li YM^*; Zhao YF

来源：International Journal of Quantum Chemistry, 2001, 83(1): 41-51.

DOI：10.1002/qua.1041.abs

• penta-coordinate phosphoric intermediates
• MNDO
• aspartic acids
• alpha-carboxylic acid
• beta-carboxylic acid

The biomimic reactions of N-phosphoryl amino acids, which involved intramolecular penta-coordinate phosphoric-carboxylic mixed anhydrides, are very important in the study of many biochemical processes. The reactivity difference between the alpha -COOH group and beta -COOH in phosphoryl amino acids was studied by experiments and theoretical calculations. It was found that the alpha -COOH group, and not beta -COOH, was involved in the ester exchange on phosphorus in experiment. From MNDO calculations, the energy of the penta-coordinate phosphoric intermediate containing five-member ring from alpha -COOH was 35 kJ/mol lower than that of the six-member one from beta -COOH. This result was in agreement with that predicted by HF/6-31G** and B3LP/6-31G** calculations. Theoretical three-dimensional potential energy surface for the intermediates predicted that the transition states 4 and 5 involving alpha -COOH or beta -COOH group had energy barriers of DeltaE = 175.8 kJ.mol(-1) and 210.4 kJ.mol(-1), respectively. So the alpha -COOH could be differentiated from beta -COOH intramolecularly in aspartic acids by N-phosphorylation.

• 出版日期2001-5-15
• 单位清华大学