Liquid protein

The first known example of a liquid protein has been made by chemists at Bristol University, opening up the possibility of a number of medical and industrial applications, including high-potency pharmaceuticals and protein-based coolants and lubricants.

Prof Stephen Mann and Dr Adam Perriman of the university’s School of Chemistry, along with Helmut Cölfen of the Max Planck Institute for Colloid and Interface Research in Germany, have made a liquid form of the iron storage protein, ferritin. 

To achieve this, the Bristol team attached positively charged amine groups to the surface of the ferritin, which then acted as binding sites for the electrostatic attachment of a negatively charged polymer surfactant.

The ferritin-polymer composite forms a solid that melts at around 30°C to a liquid crystal with an orderly orientation of particles. When heated to 50°C, the liquid appears to act like an ordinary fluid, with disorder in the positions and orientations of particles.