Table 4.
The apparent first order rate constants (kobs) determined for the 4-CB consumption in reaction solutions initially containing 8.3 μM [14C]4-CB, 29 μM wild-type or mutant CBL, 3.6 mM ATP, 15.6 mM MgCl2 and 50 mM K+HEPES (pH 7.5, 25 °C) in the absence and in the presence of CoA. Also listed are the rate constants (k1, k-1, k2, k-2), defined in Scheme 2, and derived from single turnover time course data for the reaction solutions initially containing 8.3 μM [14C]4-CB, 29 μM wild-type or mutant CBL, 3.6 mM ATP, 15.6 mM MgCl2, 50 mM K+HEPES (pH 7.5, 25 °C) and 1 mM or 15 mM CoA. See Materials and Methods for details
| kobs (s-1)a | kobs (s-1)b | k1 (s-1) | k-1 (s-1) | k2 (s-1) | k-2 (s-1) | |
|---|---|---|---|---|---|---|
| Wild-type CBL | 270 ± 10 | 350 ± 40 | 300 | 0.01 | 120 | 0.1 |
| D402P CBL | 84 ± 9 | 120 ± 20 | 120 | 10 | 0.012 | 0.002 |
| D402A CBL | 400 ± 30 | 182 ± 8 | 190 | 11.2 | 0.85 | 0.005 |
a
Reaction solutions did not contain CoA.
b
Reaction solutions contained 1 mM CoA (wild-type and D402P CBL) or 15 mM CoA (D402A CBL).