Identification of the mofying sites of mono-PEGylated salmon calcitonins by capillary electrophoresis and MALDI-TOF mass spectrometry

摘要

A capillary electrophoretic method (CE) was developed for the detemriantion of the PEG-modification sites of three positional isomers of mono-PEG modified salmon calcitonins (mono-PEG-sCTs). Resistance to proteolytic degradation on the PEG modification sites resulted in differnet patterns of CE electropherograms for the tryptic digested mono-PEG-sCTs isomers, and the PEG modification sites were assigned accordingly. The PEG-modification sites were also confirmed directly by determining the molecular masses of the tryptic digested PEG-modified fragments of respective mono-PEG-sCT by the matrix-assisted laer desorption ionization time-of-flight (MALDI-TOF) mass spectrometry.