Synapsins are membrane-associated proteins that cover the surface of synoptic vesicles and are responsible for maintaining a pool of neurotransmitter-loaded vesicles for use during neuronal activity. We have used atomic force microscopy (AFM) to study the interaction of synapsin I with negatively charged lipid domains in phase-separated supported lipid bilayers prepared from mixtures of phosphatidylcholines (PCs) and phosphatidylserines (PSs). The results indicate a mixture of electrostatic binding to anionic PS-rich domains as well as some nonspecific binding to the PC phase. Interestingly, both protein binding and scanning with synapsin-coated AFM tips can be used to visualize charged lipid domains that cannot be detected by topography alone.

Additional Metadata
Keywords AFM, Membrane proteins, Membranes, Near-field scanning optical mocroscopy, Vesicles
Persistent URL dx.doi.org/10.1002/cbic.200400097
Journal ChemBioChem
Citation
Murray, J. (Jill), Cuccia, L. (Louis), Ianoul, A.I, Cheetham, J, & Johnston, L.J. (Linda J.). (2004). Imaging the selective binding of synapsin to anionic membrane domains. ChemBioChem, 5(11), 1489–1494. doi:10.1002/cbic.200400097