Renaturation water molecules

The determination of binding and conformational changes leaves the question of the detailed structure of complexes unanswered. At present there is no absolute method for structure determination of protein-surfactant complexes apart from x-ray diffraction, which has only been applied to lysozyme with three bound SDS molecules [49]. X-ray diffraction requires a crystal, so in the case of lysozyme cross-linked triclinic crystals of the protein were soaked in 1.1 M SDS and then transferred to water or a lower concentration (0.35 M) of SDS to allow the protein to refold. It was necessary to use cross-linked crystals to prevent them dissolving when exposed to a high SDS concentration. The resulting denatured-renatured crystals were found to have three SDS molecules within a structure that was similar but not identical to that of native lysosyme. Neutron scattering has been applied in a few cases (see Sec. IX), but this is a model-dependent technique. 

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