1. S-layer proteins Potential Application in Nanobiotechnology

2. The beginning of Biotechnology

3. S-layer Proteins Challenges of Biotechnology: – Nano structured surfaces – Self assembled structures in the few to tens of nanometers – Problematic to graft with Lithographic techniques – Too big for classical chemical synthesis – Microorganisms to synthesis structures

4. S-layer Proteins Aim of Applied Molecular engineering – Design of self assembling nanostructures DNA Proteins Lipids

5. DNA self assembly

6. DNA Origami

8. S-layer Proteins DNA based functional Nanostructures: – 2D lattices – 3D cages – Networks of DNA structures interfaced with proteins, e.g. Streptavidin

9. S-layer Proteins Protein based functional nanostructures: – proteins as patterning elements – Self assembling fusion proteins to form 2D and 3D structures As an alternative to engineered and designed fusion proteins that self assemble into larger patterns is to exploit naturally self assembling proteins into crystalline patterns

10. S-layer Proteins The cell surface envelope proteins (S-layer proteins) (Sleytr et al., 1999) S-layer proteins are the outermost component of the cell envelope They represent a universal feature of archea. E.g. Haloferax Volcanii has its surface covered to 98 % with S-layer proteins Gram positive bacteria such as Micrococcus lysodeicticus contains S-layer proteins

11. S-layer Proteins S-layer lattices are composed in most cases of a single protein or glycoprotein species, that self assemble into Oblique Hexagonal Square symmetry

12. S-layer proteins

13. S-layer Proteins

14. Electron Micrograph of a gram positive bacterium with a square p4 S-layer lattice

15. S-layer Proteins

16. S-layer proteins

17. S-layer Proteins S-layer proteins are a first order self assembly system that has been optimised during the course of evolution. In bacteria the S-layer proteins are linked to each other and the underlying cell envelope by Non covalent forces These proteins can maintain their self assembly potential even after isolation.

18. S-layer Proteins

22. The s-layer cyrstal lattices as found on the outside of bacterial cells can be restored on Synthetic substrates such as. Silicon wafers Noble metal surfaces Langmuir lipid films Liposomes plastics

23. S-layer proteins

24. S-layer assembly in Solution

25. Crystal growth at interfaces

26. S-layer growth on Si surfaces

27. S-layer Proteins

28. Patterning of S-layers on Si surfaces

29. S-layer Proteins

30. S-layer Proteins patterning by soft lithography

31. S-layer Proteins

42. S-layer Proteins Biomimetic cell membranes

43. S-layer Proteins: Biomimetic lipid membrane

44. S-layer supported lipid membranes

45. S-layer Proteins