In this issue, P. Fratzl et al. review the mechanical role of metal ions in biogenic protein-based materials. How do protein–metal interactions influence properties such as hardness, toughness, adhesion, and self-healing? The Highlights deal with the characterization of nanoporous solids by three complementary techniques (J. M. Thomas and R. K. Leary) and the conversion of CO₂ to methane on copper surfaces (M. Behrens).

In the Communications section, M. Sprik et al. describe how to align electronic and protonic energy levels of proton-coupled electron transfer in water oxidation on aqueous titania (see picture). D. P. Fairlie et al. succeeded in making a cyclic heptapeptide orally bioavailable. W.-J. Xiao et al. reveal the photocatalytic generation of N-centered hydrazonyl radicals, and G. R. Newkome et al. report on the fractal design and chemical reality of a self-assembled terpyridine-Cd^II Sierpinski triangle.

• Angewandte Chemie 45/2014: Mechanics and Chemistry,
  Angew. Chem. Int. Ed. 2014, 53 (45).