Phosphorylation Analysis by MALDI-TOF MS (3) Phosphopeptide Enrichment Technique Using TiO2

Introduction

Phosphorylation of proteins is one type of post- translational modification (PTM) which is important in the control of biological functions. Recently, mass spectrometry is being applied to the analysis of phosphorylation sites. However, due to the low ratio of phosphorylation as well as the marked decrease in ionization efficiency when phosphorylation is present, it is often difficult to conduct analysis of mixtures in their original state. Over the past several years, great achievements have been realized in phosphorylation research due to research into specific phosphopeptide enrichment techniques using IMAC (Immobilized Metal Affinity Chromatography) and titanium dioxide (TiO₂). Here we describe phosphorylation analysis using a combination of TiO₂-based phosphopeptide enrichment and MALDI-MS/MS (seamless PSD).

July 8, 2009 GMT