Chapter 34 Peptides

TL;DR: The ion-exchange chromatography of peptides is well developed, can be partially or fully automated, and is so versatile that it can be used for the separation of virtually any peptide mixture.

Abstract: Publisher Summary Methods for the separation of peptides can be classified according to the nature of the properties responsible for the separation. These properties are of five types: (1) molecular or particle weight of peptides (gel permeation chromatography), (2) net electric charge (ion-exchange chromatography), (3) difference in solubility in two phases (partition chromatography), (4) adsorptive forces (adsorption chromatography), and (5) highly selective affinity to different substances covalently bound to the solid matrix (affinity chromatography). Separations based on the net electric charge of the peptide depends on the formation of multiple electrostatic bonds between charged sites on the surface of the exchanger and the opposite charge sites of the peptide. The dipolar ionic character of the peptides allows the use of both cation and anion exchangers. The only restrictions are because of the limited solubility of peptides at different pH values. Nowadays, the ion-exchange chromatography of peptides is well developed, can be partially or fully automated, and is so versatile that it can be used for the separation of virtually any peptide mixture.