Characterization of New Cyclic D,L-α-Alternate Amino Acid Peptides by Capillary Electrophoresis Coupled to Electrospray Ionization Mass Spectrometry.

Abstract

The self-assembly of peptide nanotubes (PNTs) depends on the structure and chemistry of cyclic peptide (CP) monomers, impacting on their properties, which makes the choice of their monomers and their characterization a high challenge. For this purpose, we developed for the first time a capillary electrophoresis coupled to electrospray ionization mass spectrometry (CE-ESI-MS) methodology and characterized a set of eight original CP sequences of 8, 10, and 12 D,L-α-alternate amino acids with a controlled internal diameter (from 7 to 13Å) and various properties (diameter, global surface charge, hydrophobicity). This new CE-ESI-MS methodology allows verifying the structure, the purity, as well as the stability (when stored during several months) of interesting potential precursors for PNTs that could be employed as nanoplatforms in diagnostics or pseudo sieving tools for separation purposes.