Quantitation of water in membranes by neutron diffraction and X-ray techniques.

The general principle of placing neutron and X-ray scattering density profiles on an absolute scale is being applied to an increasing number of problems in structural biology. This maximizes the information from the experiments by facilitating the identification of various molecular species. The greater detail available on the membrane water distribution has been highlighted in this chapter. The quantitative analysis of water in the headgroup region and the intermembrane water layer provides valuable information on membrane structure and function. The single most important limitation of the method is the lack of resolution. Improvements in experimental techniques will improve the resolution in a number of situations.