Purification of tryptophan containing synthetic peptides by selective binding of the alpha-amino group to immobilised metal ions
Hansen, P.; Lindeberg, G.
Journal of Chromatography. a 662(2): 235-241
ISSN/ISBN: 0021-9673 PMID: 8143027 DOI: 10.1016/0021-9673(94)80510-5
Immobilised metal ion affinity chromatography (IMAC) based on selective binding via the alpha-amino group to Cu2+ and Ni2+ ions has been used to purify tryptophan containing synthetic peptides. A free alpha-amino group, serving as an affinity handle, is present only in the target peptide when the peptides are synthesised by the solid-phase method and remaining amino groups after each coupling step are blocked by acetylation. A free alpha-amino group is necessary to retain the peptide on the column. The tryptophan residue may contribute to the binding only if the peptide is simultaneously anchored via the alpha-amino group.