Figure 7 - full size

Figure 7.
Fig. 7. a: Structure and (2|F[o]|−|F[c]|), α[c] map of trypsin–APC-11922, 1.50 Å resolution. For the major inhibitor conformer (opaque sticks) there is a hydrogen bond between the inhibitor phenol (O6′) and Nε2[His57], and a short O6′–Oγ[Ser195] hydrogen bond. b: Structure and (2|F[o]|−|F[c]|), α[c] map of uPA–APC-11421, 1.75 Å resolution. In this and all other uPA complexes of the APC-7136 analogs in Fig. 2b, the phenol hydroxyl is at or near the oxyanion hole, receiving hydrogen bonds from N[Gly193] and from the inhibitor NH amide group. In many trypsin and thrombin complexes the inhibitor is discretely disordered between the two binding modes in (a) and (b).