chapter  6
44 Pages

Fluorescence Assays For Membrane Fusion

WithNejat DÜzgÜneş, Joe Bentz

This chapter examines assays for membrane fusion: two assays for the intermixing of aqueous contents of phospholipid vesicles, and one for the mixing of membrane components. It shows that how the well-behaved fusion assay can reveal not only whether fusion has occurred, but also how much and how fast. Leakage of aqueous contents during fusion of certain types of vesicles can complicate the fitting of kinetic rate constants in contents-mixing assays. This complication can be overcome by performing a complementary experiment which measures the leakage from vesicles. The chapter provides some example of the diverse fusion behavior of liposomes of varying membrane composition and membrane curvature, discuss the problem of leakage. It outlines the applicability and usefulness of fluorescence assays in understanding the molecular mechanisms of membrane fusion in biological systems. Applications to Biological Membranes is obvious that the fusion of pure phospholipid vesicles is not expected to model every aspect of fusion events in biological membranes.