Peptide Diastereomers, Separation of
Peptides and Proteins
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Scriba, G. K. 2006. Peptide Diastereomers, Separation of. Encyclopedia of Analytical Chemistry.
- Published Online: 15 SEP 2006
Diastereomeric peptides, isomers in which one or more of the chiral centers have been converted to the opposite configuration (R or S), often possess different biological activities and/or conformational properties. Therefore, the separation and determination of diastereomeric peptides is particularly significant to the pharmaceutical industry for quality control of peptide synthesis and stability as well as for regulatory requirements. Diastereomers differ in their physicochemical properties which can be utilized for their determination by numerous techniques. In contrast to many other methods such as optical rotation, circular dichroism, differential scanning calorimetry, infrared (IR) spectroscopy, or nuclear magnetic resonance (NMR) spectroscopy only chromatographic techniques and capillary electrophoresis (CE) allow the sensitive and simultaneous identification and quantification of peptide diastereomers.
The current chapter will cover the analytical scale separation of peptide diastereomers by chromatographic methods, including paper chromatography (PC), thin-layer chromatography (TLC), gas chromatography (GC), and high-performance liquid chromatography (HPLC) as well as CE. HPLC is currently the predominant method for peptide diastereomer separations. However, due to the high resolving power particularly for polar compounds CE has been applied to the separation of diastereomeric peptides in recent years. This article will cover methods employing achiral stationary phases or buffers without chiral additives for the separations. Moreover, only examples of diastereomeric peptides containing natural amino acids will be discussed.