Orientation and two-dimensional organization of proteins at chelator lipid interfaces.

The analysis how proteins interact or assemble with each other in time and space is of central interest. Biofunctionalized interfaces can be applied to study protein-protein interactions in solution or elementary biological processes at membranes. Chelator lipid layers are well suited for these applications as they specifically bind histidine-tagged fusion proteins and further mimic the two-dimensional world of biological membranes. Here, we used green fluorescent protein (GFP) as a model to study its reversible, functional, and oriented immobilization via histidine-tag at chelator lipid interfaces by various surface sensitive techniques. Taking advantage of the self-organizing properties of chelator lipids, the association and dissociation kinetics, the surface density as well as the organization of the protein in two-dimensional arrays can be controlled. The chelator lipid system can be used for bioanalytical and structural studies as well as to examine recognition processes at membranes.