Tags aren’t always helpful.
Most recombinant proteins are expressed with tags to simplify purification. With tau, it’s different: even 6 extra residues can change folding and impact downstream aggregation assays. That’s why researchers often prefer tag-free tau. We’ve managed to find a way to get it to very high purity even without the tags.
Tau doesn’t look its size.
Theoretical molecular weight? ~60 kDa. But on HPLC, tau often behaves like a ~200 kDa protein. Why? Because it’s intrinsically disordered. Instead of a compact globular structure, tau behaves more like an extended coil, making it difficult to pin down as monomer, dimer, or oligomer. For anyone characterizing tau, size alone can be misleading.
Phosphorylation is harder than it sounds.
Phosphorylated tau is central to pathology, but reproducing it in the lab is not straightforward. Many preparations are heterogeneous, phosphorylated at multiple sites without control. Our team is working on site-specific versions, with one product already verified by Western blot (single phosphorylation site). This level of precision is critical for mechanistic studies.
The Tau monomer is the real workhorse.
Tau wants to aggregate. Left unchecked, monomers form oligomers and fibrils with ease. But aggregation studies, drug screening, and mechanistic experiments all start with monomeric tau. We’ve isolated tau in its monomeric form and confirmed it using HPLC.
Takeaway: What looks simple on paper quickly becomes complex in the lab. And that complexity, from purification to post-translational control, is exactly why tau is both a challenge and an opportunity for those tackling neurodegenerative disease.
Find out about our catalogue of over 60 Tau and related proteins in the below.
If you’ve worked with tau, what surprised you most in the lab?
Learn more at: https://www.sinobiological.com/resource/application-note/tau-proteins
