Table 2.
Kinetic constants for the rate of formation and breakdown of the gem-diamine complex for mutant rcSHMT forms with glycine and L-serine substrates.
| Substrate | pH | T253A | T253C | ||||
|---|---|---|---|---|---|---|---|
| k on (s−1 M−1 · 104) | k on′ (s−1 M−1 · 106) | k off (s−1) | k on (s−1 M−1 · 104) |
k
on′ (s−1 M−1 · 106) |
k
off
(s−1) |
||
| L-Serine | 6.4 | 3.3 | 20 | 10.3 | 2.9 | 18 | 39 |
| 6.8 | 5.8 | 14 | 8.3 | 4.0 | 10 | 36 | |
| 7.2 | 8.7 | 8.6 | 5.8 | 6.8 | 6.7 | 32 | |
| 7.6 | 9.5 | 3.7 | 5.3 | 8.7 | 3.4 | 27 | |
| 8.0 | 10.7 | 1.8 | 3.1 | 9.4 | 1.5 | 23 | |
|
| |||||||
| Glycine | 6.4 | 0.8 | 13 | 1.0 | 0.5 | 8.5 | 5.1 |
| 6.8 | 1.3 | 8.0 | 1.3 | 0.7 | 4.5 | 6.7 | |
| 7.2 | 2.1 | 5.0 | 1.9 | 1.5 | 3.8 | 6.9 | |
| 7.6 | 3.0 | 2.9 | 2.4 | 2.1 | 2.2 | 7.0 | |
| 8.0 | 4.4 | 1.8 | 2.9 | 3.7 | 1.6 | 6.8 | |