Crystallogenesis of biological macromolecules. Biological, microgravity and other physicochemical aspects

After an historical introduction and justification of the importance of proteins (as well as other macromolecules or macromolecular assemblies of biological origin) in modern biology but also in physics, this review presents the state of the field of macromolecular crystallogenesis. The basic questions underlying the crystallization of macromolecules will be addressed and discussed in a first part. The still unsolved problems are highlighted. This section also discusses the methodological approaches that can be used. In the second part, some of the recent achievements in the field are presented. We show how physical methods have contributed to a deeper understanding of protein crystallization. Emphasis is given to the parameter microgravity, since the projects concerning crystallizations in this environment have stimulated the physico-chemical research in the field. Finally, the future perspectives are outlined.