Engineering of self-assembling proteins for biosensing applications

The ability of isolated bacterial cell surface layer (S-layer) protein subunits to self-assemble into protein layers on solid surfaces makes them an almost ideal biological template for sensor oriented applications. Here, we used this remarkable property of the recombinant S-layer protein of Sporosarcina ureae bacterium to display streptavidin in defined order and orientation into two dimensional, nanosized protein lattices. We show that these lattices constitute a functional biomolecular matrix by binding biotinylated quantum dots on its surface. Therefore, they have a great application potential as sensor elements.