Towards a microarray of functional membrane proteins: Assembly of a surface-attachable, membrane-protein-anchored membrane structure using apolipoprotein A-1

Apolipoprotein A-1 (apoA-I) forms a discoidal membrane structure with phospholipids during the formation of high density lipoprotein and plays a role in the reverse cholesterol transport pathway. The discoidal membrane nanostructure, Nanodisc, can be easily assembled in vitro using apoA-I protein and phospholipids. In this study, the possibility of exploiting this unique membrane structure for the immobilization of membrane proteins on solid surfaces while the proteins are embedded in the membrane was investigated. By using His6-tagged full-length apoA-I, a surface-attachable, membrane-protein-anchored membrane (SAMPAM) structure, in which membrane proteins of interest are embedded into the membrane, was reconstituted. When the SAMPAM was immobilized on a Ni-NTA surface, the structure maintained its size and shape, indicating that the new proposed architecture may be useful for the display of membrane proteins on a solid surface in a membrane-associated form.