Figure 1.

Upper part: Details of [¹H−¹⁵N] HSQC showing resonance of residue Arg 55 of the free CypA and in the CypA−CsA and CypA−Alisporivir complexes. Superimposed are the 1D projections. From left to right, HSQC corresponding to time points 0, 341, and 744 min. Lower part: Evolution of the integrals of the resonances of Arg55 in the CypA−CsA (plain triangles) or CypA−Alisporivir (circles) complexes or in CypA (crosses), during loading of the free protein by a 1:1 Alisporivir:CsA mixture of the ligands dried on the tube walls from a chloroform solution. The sum of the signals is represented by diamonds. Time points are every 33 min, corresponding to the duration of an HSQC, except for the first HSQC of 66 min. The experiment was performed on a 900 MHz Bruker spectrometer equipped with a cryogenic probe head, using a standard 5 mm tube and a concentration of CypA of 240 μM.