“Determination of peptides by open-tubular capillary electrochromatography using a capillary chemically modified with porphyrin”

YONE A; CARBALLO R; REZZANO IN; VIZIOLI NM

Puerto Vallarta, México

Simposio; 14th Symposium on Biomedical, Biopharmaceutical and Industrial Applications of Capillary Electrophoresis and Microchip Technology; 2008

Peptides and proteins play a key role in the life processes of living organisms carrying out many different functions like hormones to antibiotics. Due to the complexity and the high variability in their chemical structure, the analysis of these biomolecules represents one of the most challenging tasks for separation techniques. Capillary electrochromatography (CEC), a hybrid technique of capillary electrophoresis and liquid chromatography, has emerged as a high-efficient and high-sensitive tool for aminoacid, peptide and protein analysis. In the last ten years, several CEC methods have been reported for monitoring the synthesis, isolation, purification, chemical derivatization and enzymatic conversions of those biomolecules, for their quality control in addition to the study of their interactions with other compounds. In this work, an open-tubular CEC (OT-CEC) method using a capillary chemically modified with protoporphyrin was developed for separation of various synthetic peptides. The migration behaviour of selected peptides has been studied at several pH values. Different concentrations of acetonitrile as an organic solvent modifier of the buffer electrolyte composition were tested. The interference of bubbles produced by the catalytic activity of the protoporphyrin and how to prevent this phenomenon will be also discussed during this presentation. Finally, the OT-CEC method was applied to the separation of tryptic peptides generated from proteins.