Figure 5
Example averaged fluorescence traces recorded under pseudo-first-order, multiple-turnover conditions (a, b) and under single-turnover conditions at near-saturating concentrations of 1b (c, d, e). (a) Quenching of the intrinsic protein fluorescence during the pre-steady-state phase of R-C1-catalyzed hydrolysis of (S,S)-1a. The averaged traces were fitted to (3), yielding two observed rates (kobs). The concentrations of substrate and enzyme are shown on the graph. (b) Transient fluorescence decay during R-C1B1-catalyzed hydrolysis of (S,S)-1a. A first-order exponential was fitted to the data (2). (c, d, e) Recovery of protein fluorescence under single-turnover conditions after R-C1-catalyzed hydrolysis of (R,R)-1b (c) and (S,S)-1b (d) and R-C1B1-catalyzed hydrolysis of (S,S)-1b (e), respectively. Solid lines are fits of (2) to the experimental data. The insets show the residuals of the fitted models. |