"Many important biological systems have the ability of transferring mechanical energy within individual molecules across distances of 1-10 nm. The mechanisms behind such energy transfer are poorly understood. Increased knowledge about them may not only explain fundamental processes in biology, but may also enable novel approaches to energy-related problems in general and new applications in supramolecular nanotechnology in particular. We propose to use physico-chemical methods to study how chemical, electrical and photochemical energy is converted into mechanical energy in supramolecular systems as models for the biological systems. We will concentrate on the energy conversion in proteins: ATP synthase, ion channel KvAP and Rad51, which each exemplifies a different solution to intra-molecular energy transfer. To enhance our mechanistic understanding, we will use model systems and methods that have previously been developed in the laboratory. We intend to build on our extensive expertise in spectroscopic methodology and exploit and develop further site-selected linear dichroism by molecular replacement (SSLD-MR) for studying structure and dynamics of the systems and their components. The studies here described constitute a new direction of research and a unique approach to addressing fundamental questions on energy conversion in biological systems. The results may give insights into important events in biology and new methodologies that enable us for the first time to study structural details of membrane proteins in membrane environment."