Advances of ionic liquids-based novel methods for proteomic sample preparation

Abstract

In-depth coverage analysis of proteome can detect the dynamic changes of protein expression in a panoramic view, which is of great significant for revealing the mechanisms of disease occurrence and development to discover new drug targets. Sample preparation is the prerequisite for proteomic analysis, in which protein extraction is crucial and affects the coverage of qualitative and quantitative analysis for proteome. However, the existing extraction reagents have insufficient dissolution ability for hydrophobic proteins, resulting in serious losses during sample preparation. Therefore, it is urgent to develop extraction reagents with strong dissolution ability for proteins, especially for hydrophobic proteins, and at the same time with good compatibility to subsequent enzymatic hydrolysis and liquid chromatography-mass spectrometry analysis. Recently, due to the strong dissolution ability, ionic liquids (ILs) have gradually been used for dissolving, extracting, and separating individual proteins. ILs have also begun to show their advantages in the preparation of complex proteomic samples, showing excellent proteome extraction performance. Herein, we systematically summarize the IL-based sample preparation methods for membrane proteome, whole proteome and post-translational modification proteome and further explore the interaction mechanism between ILs and proteins. The wide application of ILs in proteomic analysis is also prospected in this review.