title: Facile analysis and purification of deblocked N-terminal pyroglutamyl peptides with a strong cation-exchange sulfoethyl aspartamide column.
abstract: A high-performance strong cation-exchange Sulfoethyl Aspartamide column was used to analyze and purify five N-terminal pyroglutamyl peptides after treatment with Pyroglutamate Aminopeptidase. The resulting deblocked N-1 peptides possess an increased positive charge and are therefore retained to a greater extent by the column. Salt gradient elution in a pH 3 mobile phase was then used to recover the desired peptides and the purified deblocked peptides were directly subjected to N-terminal sequence analysis. The same digests were also chromatographed on a C18 reversed-phase column using standard trifluoroacetic acid-acetonitrile gradient elution. The elution order for the parent peptide and the N-1 peptide on the reversed-phase column was reversed from that on the Sulfoethyl Aspartamide column and the resolution of the two peptides obtained on the reversed-phase column was less than that observed on the cation-exchange column. In addition, the Sulfoethyl Aspartamide column was shown to be useful to monitor the extent of N-terminal glutamine cyclization formed during peptide purification and storage.
mesh_terms: D000476:Alkanesulfonates; D000626:Aminopeptidases / Q000378:metabolism*; D000808:Angiotensinogen / Q000032:analysis / Q000378:metabolism; D001839:Bombesin / Q000032:analysis / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D026261:Diazepam Binding Inhibitor; D004600:Eledoisin / Q000032:analysis / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis / Q000378:metabolism; D009479:Neuropeptides / Q000032:analysis / Q000378:metabolism; D009496:Neurotensin / Q000032:analysis / Q000378:metabolism; D009842:Oligopeptides / Q000032:analysis / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D010455:Peptides / Q000032:analysis* / Q000378:metabolism; D011751:Pyroglutamyl-Peptidase I / Q000378:metabolism*; D011760:Pyrrolidinones; D011761:Pyrrolidonecarboxylic Acid; D015375:Receptors, Interleukin-2 / Q000032:analysis / Q000378:metabolism; D012822:Silicon Dioxide; D013722:Teprotide; D013935:Thymic Factor, Circulating / Q000032:analysis / Q000378:metabolism
chemical_list: D000476:Alkanesulfonates; D026261:Diazepam Binding Inhibitor; D009479:Neuropeptides; D009842:Oligopeptides; D010446:Peptide Fragments; D010455:Peptides; D011760:Pyrrolidinones; D015375:Receptors, Interleukin-2; C067529:diazepam binding inhibitor (33-50); C057181:poly(2-sulfoethyl aspartamide)silica; D000808:Angiotensinogen; D007987:Gonadotropin-Releasing Hormone; D009496:Neurotensin; D004600:Eledoisin; D012822:Silicon Dioxide; D013935:Thymic Factor, Circulating; D013722:Teprotide; D000626:Aminopeptidases; D011751:Pyroglutamyl-Peptidase I; D001839:Bombesin; D011761:Pyrrolidonecarboxylic Acid