We propose to computationally design novel ligand binding and catalytically active proteins by harnessing the high thermodynamic stability of de novo helical proteins. We aim to: -Characterize to which extent we can harness the stability of parametrically designed helical bundles to introduce deviations from ideal geometry. -Develop a new computational design strategy, which expands on the Crick coiled-coil parametrization and allows to rationally build non-ideal helical protein backbones at specified regions in the desired structure. -Investigate new strategies to design the first cascade reactions into de novo designs.