Recombinant production and purification of the human protein Tau.

Tau protein is a microtubule-stabilising protein whose aggregation is linked to Alzheimer's Disease and other forms of dementia. Tau biology is at the heart of cytoskeletal dynamics and neurodegenerative mechanisms, making it a crucial protein to study. Tau purification, however, is challenging as Tau is disordered, which makes it difficult to produce in recombinant system and is degradation-prone. It is thus challenging to obtain pure and stable preparations of Tau. Here, we present a fast and robust protocol to purify Tau recombinantly in Escherichia coli. Our protocol allows purifying Tau either tag-less or FLAG-tagged at its N-terminus, and Tau fragments of interest. By exploiting a cleavable affinity tag and two anion exchange columns, we obtained Tau preparations of high purity, stable and suitable for in vitro studies, including aggregation experiments that resemble neurodegenerative processes.