Bacterial cell surfaces
Combined molecular approaches have determined bacterial proteins that are exposed for interaction with the immune system. Knowing the coverage height of the lipopolysaccharide (5-10 nm) layer and capsule polysaccharide (375 nm) layer has enabled us to build a topographical map that includes the cell surface proteins of capsulated and uncapsulated bacteria. This relies on new applications of imaging technologies such as super-resolution microscopy and atomic force microscopy. Just six types of proteins extend beyond the 5 nm boundary, and bioinformatic tools have been refined to scan genome datasets to determine those proteins that extend far enough to bind host cell surfaces.
In parallel with these studies, we are working to understand the mechanism by which these outer membrane proteins are assembled onto the bacterial cell surface. The catalysts of this assembly represent exciting new targets for anti-infective therapies.