POLYMER-COATED REVERSED-PHASE PACKINGS WITH CONTROLLED HYDROPHOBIC PROPERTIES .2. EFFECT ON THE SELECTIVITY OF PEPTIDE SEPARATIONS

We have designed and synthesized novel reversed-phase packings of non-porous and porous polymethacrylate-coated silicas. By varying the hydrophobicity of the polymer coating, selective unfolding of polypeptides may be achieved, thus enabling manipulation of the chromatographic profile. This study characterizes these packings through their employment for separations of model synthetic peptides of defined secondary, tertiary and quaternary structure. Thus, the packings were applied to the reversed-phase separation of alpha-helical amphipathic and non-amphipathic peptides of the same amino acid composition but different sequences. In addition, selective unfolding of model two-stranded alpha-helical coiled-coil peptides was achieved with these packings. Through the observation of the chromatographic behaviour of these model peptides on the various polymethacrylate-coated silicas, we were able to confirm the potential of such tailored packings for separations of peptides and proteins.