“…Information concerning the environment and location of tryptophan side chains and the changes in environment of these residues due to structural transformations can be gained by ultraviolet difference spectroscopy and fluorescence measurements. However, since these two techniques are weil known to biochemists and have been reviewed extensively (55,101,116,172,410,411), it was decided to Iimit the following presentation to other modern spectroscopic tools. Among those particularly worthy of mention appear to be circular dichroism, magnetic circular dichroism, circular polarization of fluorescence, nuclear magnetic resonance eH, 13 C, 14 N) and X-ray diffraction.…”