Latent analysis of unmodified biomolecules and their complexes in solution

Emma V. Yates, Thomas Müller, Luke Rajah, Erwin J. De Genst, Paolo Arosio, Sara Linse, Michele Vendruscolo, Christopher M. Dobson, Tuomas P.J. Knowles.

Nature Chemistry 7(10):802-9, 2015.

In this paper, Yates et al show that the technology behind Fluidic Analytics instruments—microfluidic diffusional sizing—can be used to accurately size a range of proteins. Results were compared to those obtained using Pulsed Field Gradient NMR and Analytical Ultracentrifugation and found to agree closely (Figure 1).

Sizing proteins, heterogeneous mixtures and protein complexes.
Figure 1: MDS is used for size determination of various proteins Rh values determined in this manner are compared to those obtained with PFG-NMR (lilac) and AUC (aqua). The studied molecules vary by over three orders of magnitude in molecular weight and include intrinsically disordered proteins and heterogeneous mixtures.

 Finally, they demonstrate that Microfluidic Diffusional Sizing can be used to characterise protein interactions without the use of tags, using the platform to explore the binding of α-synuclein to a nanobody, NbSyn1 (Figure 2).

novel Parkinson's-related immune complex
Figure 2: MDS is utilised to characterise protein interactions without the use of tags. Characterisation of a novel Parkinson’s-related immune complex between a Nanobody and equimolar (5 μM) α-synuclein.