PROTEINS AND PEPTIDES AS CHIRAL SELECTORS IN LIQUID-CHROMATOGRAPHY

Considerable progress has been made recently in the application of amino acid-derived chiral selectors to direct enantiomer separations by liquid chromatography. A better understanding of the chiral discrimination exerted by proteins has been achieved through detailed analyses of the adsorption isotherms obtained under various mobile phase conditions and temperatures. Further insight into the complexity of protein-ligand interactions and the effect on retention have come from studies with the use of mobile phase additives causing allosteric interaction, sometimes resulting in dramatic effects on the enantiomeric separation factor. Further, the recent use of small, synthetic peptides as chiral selectors has shown promise for the future. The wide applicability of particularly the protein phases has led to a variety of novel experimental techniques, involving miniaturization (capillary LC and its combination with mass spectrometry), use for electrically driven separations (capillary electrophoresis), immobilization of proteins on so-called continuous gels for rapid enantiomer separations and use for studies of enzyme stereochemistry.