Exploring Phosphoinositide Binding Using Native Mass Spectrometry.

Phosphoinositides interact with proteins to fulfill various functions in the cell. In many cases, they specifically recruit peripheral membrane proteins to biological membranes. The analysis of their interactions with proteins is therefore essential for understanding the underlying processes. Native mass spectrometry (MS) preserves noncovalent interactions in the gas phase of a mass spectrometer and is therefore well-suited to study protein-phosphoinositide interactions. In this protocol, we describe the application of native MS to integral and peripheral membrane proteins and their interactions with lipids. We discuss sample and instrumental requirements, the realization of experiments, and the data analysis workflow. We further describe a biochemical assay to proof interactions of peripheral membrane proteins with lipids.