Peptide mapping through the coupling of capillary electrophoresis and high-performance liquid chromatography: map prediction of the tryptic digest of myoglobin.

The tryptic map of horse myoglobin was analysed through capillary electrophoresis using capillaries modified by a monolayer of acrylamide. The results were reproducible and the map was obtained in less than 30 min from ca. 8 pmol of tryptic digest. The peptide identification was performed using peptides previously identified by high-performance liquid chromatography. The peak areas measured using the two techniques are closely related, and the comparison of elution and migration times shows that the two techniques provide different maps. Furthermore, using the semiempirical relationship suggested by Grossman et al. [Anal. Biochem., 179 (1989) 28], which links the electrophoretic mobility to the charge of the peptide and its number of amino acids, a good agreement between predicted and experimental mobilities was observed.