Non-radioactive determination of phosphoamino acids in peptides and proteins by capillary electrophoresis

摘要

A new method is described that allows non-radioactive determination of all phosphoamino acids in peptides or proteins. It involves partial hydrolysis of peptides or proteins using 6 N HCl at 110 deg C for 1.5 hour, then derivatization of the liberated amino acids with phenylisothiocyanate and finally separation of all PTH-phosphoamino acids from other PTH-amino acids or peptides by capillary electrophoresis. The detection limits are 170 fmol for phosphotyrosine, 350 fmol for phosphothreonine and 700 fmol for phosphoserine.