Supramolecular Organization of Oligopeptides, through Complexation with Surfactants We thank the Max Planck Society and the Fund of the German Chemical Industry for financial support. Technical help by Rona Pitschke, Bernd Smarsly, and Ingrid Zenke for carrying out the SAXS measurements is gratefully acknowledged.

Ionic self-assembly: Oligopeptides with a small number of charged sites can be precipitated from water by complexation with oppositely charged surfactants, as exemplified here with oxidized glutathione, GSSG. These complexes are well-defined 1:1 species, dissolve in organic solvents, and form highly organized supramolecular aggregates (solution; see schematic representation) or mesophases (solid-state films). This ionic self-assembly with surfactants represents a simple access to new peptide superstructures with structural features on the nanometer scale.