Phospholipases to recognize model membrane structures on a molecular length scale

Phospholipases are enzymes that hydrolyze different phospholipids within biomembranes to produce messenger molecules for the cellular signal transduction. Their activity is highly dependent on the lipid membrane structure as described in this review. In particular, the secretory phospholipase A2 (sPLA2) is activated through liquid–liquid phase boundaries and membrane curvature on a nanometer-length scale. The local enrichment of lipid activators within membrane domains has been shown to efficiently enhance the activity of sPLA2 as well as of bacterial phospholipase D (PLD). Thus, phospholipase activity has been correlated to the underlying lipid phase diagrams. This allows the use of phospholipases as molecular probes to unravel model membrane structure with very high resolution.