As an efficient and facile reaction, click chemistry has been growingly used in the preparation of chromatography media for immobilizing varying types of ligands. For the widely used Cu (I)-catalyzed alkyne-azide click reaction, a 1, 2, 3-triazole group will be inevitably introduced in the molecular linkage, which could give rise to unexpected non-specific adsorption especially for the media employing small compound ligands or high ligand density. Triazole-induced non-specific protein adsorption on sepharose resins was evaluated systematically in this work, by considering the effects of triazole content, length of spacer arm, and solution conditions. We found that triazole content of a resin played the key role. Protein adsorption became significant when the media was coupled with triazole at a medium density (about 60μmol/mL gel), and the binding amount further increased with triazole density. The resin with triazole content of about 100μmol/mL gel could adsorb human IgG, bovine serum albumin and lysozyme at the amount of 13.6, 30.0, and 5.1mg/mL respectively. Proteins tended to be adsorbed at higher amount as the pH of solution approached their isoelectric points, and increasing salt concentration could reduce triazole-induced adsorption but only within limited extent. This study can facilitate reasonable application of click chemistry in the synthesis of chromatography media, by providing some basic principles for optimizing structural properties of separation media and choosing suitable solution conditions.
Keywords: Chromatography media; Click chemistry; Ligand immobilization; Non-specific adsorption; Triazole.
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