Figure 4: Secondary chemical shift analysis extrapolated for theD0 state of mHIV-1-PR1-95 . For each residue, the chemical shifts under different experimental conditions were extrapolated to zero denaturant. Here we report the average of these extrapolations. The secondary chemical shifts were calculated by the use of the intrinsic random coil reference. The error bars indicate the total error of the procedure. Different nuclei were monitored (a) Cα, (b) C , (c) N and (d) HN. The secondary structure of mHIV-1-PR1-95 is shown at the top.