The interaction between proteins is central not only to this thesis, but to most processes in the cell. After millions of years of evolution, the accomplished variety, complexity and beauty of the proteomic network is astonishing. When one realizes that these interplays rely on the delicate process of protein folding, a very special sort of protein interaction comes into play: that between molecular chaperones and their clients. Chaperones are specialized proteins crucial to protein folding. They are thought to guide polypeptides through their conformational search from synthesis, preventing alternative hazardous pathways, and to rescue proteins from misfolded and aggregated states....@en