Fig. 5.

Influence of the conformation of the MTSL tag on paramagnetic relaxation enhancement in CylR2 55R1. a Theoretical positions of the paramagnetic oxygen in the 3D structure of CylR2 for conformations of the MTSL tag from the T4L structure. Left hand side: oxygen positions C1 (Magenta), C2 (orange), C3 (yellow), C4 (green) and C5 (blue) for the 72R1 conformations listed in Table 1. Right hand side: positions corresponding to 131R1. The oxygen location observed in the crystal structure of CylR2 55R1 is shown in red. Two views related by a 90° rotation are presented. b Comparison of the experimental PRE intensity profile (black) with the pattern calculated for the 131R1 C2 conformation (grey). Error bars were obtained from repeat measurements. Note the large deviation between the two profiles in comparison to Fig. 4