Fig 3.

Binding and interaction between tau and glycogen synthase kinase-3β (GSK3β) in co-immunoprecipitation and nanobeam experiments. (a) Co-immunoprecipitation of tau and GSK3β in SY5Y cells with or without sevoflurane or testosterone treatment. (b) Nanobeam sensor centre and resonance measurement set-up. (c) Schematic of the microfluidic channel showing tau interacting with GSK3β. (d) Real-time recording schematic of the interaction between tau and GSK3β. The shifting of spectrum wavelength indicates changes in binding signals in different conditions. Specifically, shifting from black or purple to red or dark blue represented the interaction of tau and GSK3β; shifting from red or purple to blue or dark blue reflects binding between tau and GSK3β after wash-off of weak interactions between tau and GSK3β. (e) Nanobeam signal recording of all time points showing the interaction between tau and GSK3β without testosterone treatment (Phase I; coloured area) and with testosterone treatment (Phase II; uncoloured area). There was a larger signal reduction between GSK3β plus testosterone and the second wash (e) (Phase II; uncoloured background) vs between GSK3β plus vehicle and the first wash (e) (Phase I; coloured background), suggesting that the interaction between tau and GSK3β was reduced by testosterone. a.u., arbitrary unit; Δ, delta, representing changes; λ, nanobeam wavelength.