1. Daniel J. Muller, Wolfgang Baumeister, and Andreas Engel
Conformational Change of the Hexagonally Packed Intermediate Layer of Deinococcus radiodurans Monitored by Atomic Force Microscopy
Daniel J. Muller, Wolfgang Baumeister, and Andreas Engel
Presented by Robert Warden

2. Bacterial Surface Layers
Protein layer surrounds cells
Usually a single protein
Self-assemble into regular patterns
Hydrophobic/hydrophilic sides
Involved in transport two and from cell
D. radiodurans S-Layer
Hexagonal 6-mer
Well-characterized structurally and biochemically

3. Atomic Force Microscopy
Protein in native environment
Different cantilevers
Hydrophilic – Si3N4
Hydrophobic – Carbon
Forces of <0.2 nN
Study dynamic processes

4. AFM Images Consistent with previous studies
Images of inner surface (hydrophobic)

5. Dynamic Studies Spontaneous open/closed shift
Not effected by change of cantilever
Open to Closed
5 min
Closed to Open

6. Significance AFM can be done in native environment Dynamic Information
Forces too small to disrupt structure
Proteins can be adsorbed to surface
Dynamic Information

7. Questions?