Figure 4.

Discrimination between stably associated and isolated helices in RSV P_127–205 by variable pressure NMR experiments. (A) Overlay of ¹H-¹⁵N HSQC spectra of P_127–205 acquired by increasing pressure from 1 to 2500 bar. NMR data were recorded at 600 MHz ¹H Larmor frequency. The temperature was 313 K. (B) First and second order pressure coefficients, B₁ and B₂, were determined by fitting ¹H and ¹⁵N chemical shift variations as a function of pressure to a second-order polynomial according to δ(P) − δ(P₀) = B₁ × (P − P₀) + B₂ × (P − P₀)², and plotted with bar diagrams. Reference values for random coil conformation (taken from [60]) were plotted as red lines (B₁, solid line) and (B₂, dotted line).