Orientation of the peptide formation of N-phosphoryl amino acids in solution

The peptide formation of N-phosphoryl aminoacids with amino acids proceeds in aqueous solution withoutany coupling reagents. After being separated in sephadex gelcolumn, the phosphoryl dipeptides were analyzed by theelectrospray ionization tandem mass spectrometry (ESIMS/MS). The result demonstrates that phosphoryl dipeptideswere datected in all the reaction systems. It is found tkat theformation of N-phosphoryl dipeptides is oriented: theN-terminal amino acid residues of the N-phosphoryl dipep-tides are from N-phosphoryl amino acids, and the peptideelongation happened at the C-terminal. Only adipeptide, noβ-dipeptide, is formed in the N-phosphoryl dipeptides,showing that α-carboxylic group is activated selectively byN-pbosphorylation. Theoretical calculation shows that thepeptide formation of N-phosphoryl amino acids might hap-pen through a pentu-coordinate carboxylic-phosphoric in-termediate in solution. These results might give some clues tothe stlidy on the origin of proteins and protein

The peptide formation of N-phosphoryl amino acids with amino acids proceeds in aqueous solution without any coupling reagents. After being separated in sephadex gel column, the phosphoryl dipeptides were analyzed by the electrospray ionization tandem mass spectrometry (ESIMS/ MS). The result demonstrates that phosphoryl dipeptides were detected in all the reaction systems. It is found that the formation of N-phosphoryl dipeptides is oriented: the N-terminal amino acid residues of the N-phosphoryl dipeptides are from N-phosphoryl amino acids, and the peptide elongation happened at the C-terminal. Only a-dipeptide, no β-dipeptide, is formed in the N-phosphoryl dipeptides, showing that a-carboxylic group is activated selectively by N-phosphorylation. Theoretical calculation shows that the peptide formation of N-phosphoryl amino acids might happen through a penta-coordinate carboxylic-phosphoric intermediate in solution. These results might give some clues to the study on the origin of proteins and protein biosynthesis.