CZE separation of thymopoietin oligopeptides

The behavior of 25 thymopoietin oligopeptides was studied by capillary zone electrophoresis. The separation of diastereomeric tripeptides can be expla ined by the different configurations. The pH dependent separation of the st ructural isomers and compounds differing shlightly in side-chain length is due to the different extents of ionization. In the pH range studied the mob ility of compounds was more influenced by the dissociation of carboxylic gr oups than by the protonation of amino groups. The slightly different compou nds are separated from each other in the pH range near the pK values of the slightly different functionalities. The mobility is affected by the length of the side-chain only if it contains a functional group.