Efficient Protein Digestion at Elevated Temperature in the Presence of Sodium Dodecyl Sulfate and Calcium Ions for Membrane Proteomics.

The growing significance of membrane proteins inspires continuous development and improvement of methods for robust membrane proteomics. Here, we developed a very simple and efficient method for membrane protein digestion using an ionic detergent, sodium dodecyl sulfate (SDS), at high temperature, conditions where trypsin is normally inactivated. Our results suggest that trypsin can be stabilized by a combination of calcium ions and sodium chloride, which enables protein digestion at elevated temperature in the presence of strong ionic detergents such as SDS. Finding the conditions for stabilization of trypsin offers novel opportunities for the application of detergents for the investigation of membrane proteins.