Edward H Snell

Small angle solution scattering (SAS) is increasingly being applied to biological problems. It is a complementary technique that, when applied in appropriate circumstances with carefully structured questions, can provide unique information not available from other techniques. While small angle solution scattering has been around for some time, a confluence of recent developments has dramatically enhanced its power. Intense third generation X-ray sources, low noise detectors, development of new algorithms and the computational power to take advantage of these have all matured, and use of free-electron x-ray laser sources is on the horizon. Whole new classes of experiments and analyses have been created as a result. These include the generation of molecular envelopes, the ability to do time-resolved studies, and the ability to account for structural changes using modelling based on the SAS data. The technical improvements have also reduced the amount of time and material needed to carry out an experiment. Beamtime at synchrotron sources is in demand, workshops on the subject are popular and researchers adopting the technique as part of their repertoire are growing. With these in mind, this book was written to guide structural biologists who may wish to adopt the technique, understand its strengths and weaknesses or just have a general interest in its potential.

The crystallization of proteins and nucleic acids and/or their complexes has become more highly automated but is still often a trial and error based approach. In parallel, a number of X-ray diffraction based techniques have been developed which explain the physical reasons limiting the resulting crystallographic data and thus show how that data may be improved. Crystal growth is also pivotal in neutron crystallography, which establishes the hydrogen and hydration aspects. Thus this book is aimed at addressing the science behind obtaining the best and most complete structural data possible for biological macromolecules, so that the detailed structural biology and chemistry of these important molecules emerge. Crystal imperfections such as twinning and lattice disorders, as well as multiple crystal situations, and their possible remedies, are also described. The small crystal frontier in micro-crystal crystallography, crystallites in powders and finally down to the proposed single molecule structure determination of X-ray lasers are covered. Overall this interdisciplinary book will interest crystal growers, X-ray and neutron physicists and the biological crystallographers, including graduate students.