ABSTRACT
Histidine-rich peptides (HRPs) from human parotid saliva were reported by J. J. Pollock et al. to exert antifungal activity against Candida albicans. The HRPs obtained from the synthesis were contaminated with side products such as peptides of deleted sequences. These peptides are extremely hydrophilic because of the presence of multi-histidines and, therefore, exhibit short retention times in reversed-phase high-performance liquid chromatography (HPLC), making purification by this technique alone difficult. To improve the separation of the peptides, a multi-column approach was applied to their purification, involving the combined use of separation modes which utilize different selectivities. The chapter describes the successful purification, in high yield, of HRP-6 using the multi-column approach to preparative peptide purification. Strong cation-exchange chromatography is the most useful mode of ion-exchange chromatography for multistep peptide separations due to the ability of strong cation-exchange packings to retain their negatively charged character in the acidic to neutral pH range.
