MALDI/MS Comparison of Fe-NTA Immobilized Metal Affinity Chromatography and Commercially-Available Metal Oxide Affinity Resins for Phosphopeptide Enrichment

摘要

Immobilized metal ion affinity chromatography in combination with mass spectrometry has been used to determine the extent of phosphorylation and the specific sites of phosphorylation on proteins. There are several advantages to this combined approach. Immobilized metal ion affinity chromatography is the use of resins with metal constituents and metal oxides to enrich and isolate phosphopeptides. By selectively enriching phosphopeptides on media prior to MS analyses, suppression effects can be greatly reduced. In this report, we have investigated several resins from various sources to assess the phosphopeptide enrichment capabilities of each prior to mass spectrometric analyses. The phosphopeptide enrichment capabilities of six different resins, Glygen TiO2, ZrO2, and mixed ZrO2 and TiO2 NuTips, Titansphere TiO2 resin, PhosTrap magnetic titanium beads, and a Fe-NTA resin, are compared.