A novel pH-dependent dimerization motif in β-­lactoglobulin from pig (Sus scrofa)

The structure of porcine β-lactoglobulin shows a novel and unusual dimerization motif not previously seen in members of the lipocalin family. This partially explains the markedly different physicochemical properties of porcine and bovine β-lactoglobulin, despite these proteins sharing 66% amino-acid identity.

Screening crystallisation conditions using fluorescence correlation spectroscopy

We investigate the potential of fluorescence correlation spectroscopy (FCS) in screening for crystallisation conditions. Solutions that nucleate protein crystals must have different interactions than solutions that do not give rise to crystals. Due to these different interactions the average mean squared displacement of the individual proteins changes. By monitoring protein self-diffusion, we can distinguish crystallising from non-crystallising solutions. The method introduced can be applied at extremely low concentrations in femtoliter volumes as an early diagnostic for molecular association. Based on our preliminary findings FCS has the potential to become a routine screening method for crystallography.

The prospects of protein nanocrystallography

Progress in the development of nanocrystallography is discussed and the remaining bottlenecks are highlighted.