Table 2.
KIE and LFER data for uncatalyzed and PP1-catalyzed reactions. The standard errors in the last decimal place are given in parentheses. The rate of the uncatalyzed reaction of the monoester required that these KIEs be measured at 95 °C. The faster rate of the phosphonate reaction with hydroxide permitted its hydrolysis to be performed at 25 °C. (a) These values are the range of KIEs reported for the reactions catalyzed by the native PTPs YopH,26 VHR,27 and PTP1.26 (b) These values are the range of KIEs for reactions catalyzed by general acid mutants of the PTPs listed.
| Results for reactions of p-nitrophenyl phosphate (4NPP) | ||||
|---|---|---|---|---|
| Isotope Effect | Dianion H2O attack, 95° C28 | PP1-catalyzed | PTP-catalyzeda | PTP D to N mutant-catalyzedb |
| 18knonbridge | 0.9994 (5) | 0.9959 (4) | 0.9998-1.0003 | 1.0019-1.0024 |
| 18knonbridge per atom | 0.9998 (5) | 0.9986 (4) | 0.9999-01.0001 | 1.00060-1.0008 |
| 18knonbridge | 1.0189(5) | 1.0170(3) | 1.0118-1.0152 | 1.0275-1.0297 |
|
15k |
1.0028(2) |
1.0010(2) |
0.9999-1.0001 |
1.0024-1.0030 |
| βLG | -1.23 | -0.32 | 0.0 to -0.0729 | |
| Results for reactions of p-nitrophenyl methylphosphonate (4NPMP) | |||
|---|---|---|---|
| Isotope Effect | Monoanion -OH attack, 25° C | PP1 -catalyzed | Range of values for hydrolysis of diesters23 |
| 18knonbridge | 1.0015(4) | 0.9973 (4) | 1.0028-1.0056 |
| 18knonbridge per atom | 1.0008(4) | 0.9988 (4) | 1.0014-1.0028 |
| 18knonbridge | 1.0098(4) | 1.0129(3) | 1.0042-1.0063 |
|
15k |
1.0006(3) |
1.0010(1) |
1.0007-1.0016 |
| βLG | -0.69 | -0.30 | |