FIGURE 5.

Velocity/substrate concentration curves for wild-type (WT) SalR and selected mutants exhibiting substantial substrate inhibition. The enzyme assays were performed as described under “Experimental Procedures” in the presence of 250 μm NADPH as cofactor. The activities were calculated based on signal intensities at 210 nm of salutaridine substrate and 7(S)-salutaridinol product after HPLC separation. The numerical parameters for all curves are shown in Table 1. The open symbols are: squares, K186V; triangles up, L266A; stars, F104A-I275A; circles, I275A; triangles down, N272A. The closed symbols are: circles, WT; triangles up, M271A; triangles down, L185A.