More hydrogen bonds for the (structural) biologist

Why does a given protein structure form and why is this structure stable? T hese fundamental biochemical questions remain fascinating and challenging p roblems because the physical bases of the forces that govern protein struct ure, stability and folding are still not well understood. Now, a general co ncept of hydrogen bonding in proteins is emerging. This concept involves no t only N-H and O-H donor groups, but also G-H, and not only N and O as acce ptor groups, but also pi -systems. We postulate that the incorporation of t he entirety of these interactions leads to a more complete description of t he problem, and that this could provide new perspectives and possibly new a nswers.