Figure 2.
Selected 1H NMR assays of HppE with substrate analogues: (a) 43, (b) (R)-44, (c) preincubation with (R)-44 followed by the addition of 15, and (d) preincubation with 17 followed by the addition of 15. The bottom trace in panels (a) and (b) is the spectrum taken 3 min after mixing HppE with the substrate analogue, and the top trace is recorded 27 min after initiation of the reaction. The NMR signals and the corresponding protons in the structures shown in Scheme 5 are color-coded.