Open-tubular capillary electrochromatography using covalently attached iron-protoporphyrin for synthetic peptide analysis

YONE A; CARBALLO R; REZZANO IN; VIZIOLI NM

Santiago de Chile, Chile

Simposio; 13th Symposium on Biomedical, Biopharmaceutical and Industrial Applications of Capillary Electrophoresis and Microchip Technology; 2007

The increasing characterization of protein structures via tryptic mapping methods has created a need for better resolution in the separation of complex protein and peptide mixtures. CE and CEC have demonstrated a broad applicability in the field of aminoacid, peptide and protein separations by development of different modes of both techniques. In this work, iron protoporphyrin IX (Fe-ProP) was investigated with respect to its capability to help resolution of seven model peptides in open tubular-CEC (OT-CEC). Fe-ProP was covalently attached to the inner surface of a fused silica capillary column (50 mm id x 35 cm long). Running buffer composition was evaluated and a 25 mM potassium phosphate solution, pH 3.5, containing 5 % acetonitrile gave better resolution and peak shape. System selectivity resulted in a complete separation of the seven model peptides in less than 15 min. The OT-CEC method was applied for the determination of peptide profile from a tryptic digest of a recombinant protein.