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Differentiation of α‐COOH from β‐COOH in aspartic acids by N‐phosphorylation
Author(s) -
Chen ZhongZhou,
Tan Bo,
Li YanMei,
Zhao YuFen
Publication year - 2001
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.1041
Subject(s) - chemistry , mndo , intramolecular force , reactivity (psychology) , phosphoric acid , medicinal chemistry , phosphorylation , stereochemistry , aspartic acid , amino acid , transition state , ring (chemistry) , computational chemistry , organic chemistry , molecule , catalysis , biochemistry , medicine , alternative medicine , pathology
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 α‐COOH group and β‐COOH in phosphoryl amino acids was studied by experiments and theoretical calculations. It was found that the α‐COOH group, and not β‐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 α‐COOH was 35 kJ/mol lower than that of the six‐member one from β‐COOH. This result was in agreement with that predicted by HF/6‐31G** and B3LYP/6‐31G** calculations. Theoretical three‐dimensional potential energy surface for the intermediates predicted that the transition states 4 and 5 involving α‐COOH or β‐COOH group had energy barriers of Δ E =175.8 kJ⋅mol −1 and 210.4 kJ⋅mol −1 , respectively. So the α‐COOH could be differentiated from β‐COOH intramolecularly in aspartic acids by N‐phosphorylation. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 41–51, 2001