Interactions at the membrane surface studied by spin label ESR spectroscopy.

A range of different types of interactions at biological membrane surfaces have been studied using various different spin label electron spin resonance (ESR) techniques. These include: (1) the interfacial ionization of local anaesthetics, (2) the binding of peripheral membrane proteins, (3) the membrane insertion of translocation-competent precursor proteins and other components of the protein translocation machinery, (4) the interactions of ganglioside sphingolipids with membrane proteins, and (5) the specific surface recognition of biotinylated phospholipid headgroups by avidin. A description of these illustrates both the capabilities of this biophysical methodology and the functional/technological implications of these interactions and dynamic/thermodynamic processes for cell membranes and their surfaces.