Table 1.
Catalytic parameters (kcat, Km, and kcat/Km) of substrate hydrolysis by AChE and BChE.
| AchE |
BChE |
||||||
|---|---|---|---|---|---|---|---|
| Structure |
kcat x 103 (min-1) |
Km x 10-6 (M) |
kcat/Km x 107 (min-1 M-1) |
kcat x 103 (min-1) |
Km x 10-6 (M) |
kcat/Km x 107 (min-1 M-1) |
|
| Choline Thioesters & Esters | |||||||
| 1 |
|
70052 | 15052 | 46052 | 5055 | 4055 | 13055 |
| 2 |
|
26052 | 17552 | 15052 | 1352 | 140052 | 1252 |
| 3 |
|
Not a substrate | Not a substrate | Not a substrate | 2452 | 1852 | 13052 |
| 4 |
|
Not a substrate* | Not a substrate* | Not a substrate* | 8056 | 91056 | 8.856 |
| 5 |
|
Not a substrate | Not a substrate | Not a substrate | 5.81 ± 0.27 | 59.2 ± 7.4 | 9.88 ± 0.79 |
| 6 |
|
Not a substrate | Not a substrate | Not a substrate | 2.60 ± 0.14 | 8.93 ± 0.55 | 29.2 ± 2.79 |
| Alkyl N-Methylpiperidinyl Thioesters & Esters | |||||||
| 7 |
|
95.6 ± 17.1 | 2440 ± 492 | 3.93 ± 0.09 | 2.00 ± 1.08 | 1160 ± 740 | 0.179 ± 0.02 |
| 8 |
|
19.6 ± 14.4 | 3730 ± 2570 | 0.52 ± 0.05 | 65.4 ± 19.2 | 13000 ± 6700 | 0.545 ± 0.119 |
| 9 |
|
Not a substrate | Not a substrate | Not a substrate | 10.4 ± 1.6 | 534 ± 85 | 1.95 ± 0.01 |
| 10 |
|
Not a substrate* | Not a substrate* | Not a substrate* | 45.5 ± 23.4 | 11100 ± 4230 | 0.398 ± 0.083 |
| Aryl N-Methylpiperidinyl Thioesters & Esters | |||||||
| 11 |
|
Not a substrate | Not a substrate | Not a substrate | 0.212 ± 0.010 | 15.8 ± 1.3 | 1.34 ± 0.04 |
| 12 |
|
Not a substrate | Not a substrate | Not a substrate | 0.0621 ± 0.0044 | 24.5 ± 3.3 | 0.256 ± 0.034 |
| 13 |
|
Not a substrate | Not a substrate | Not a substrate | 0.629 ± 0.079 | 85.7 ± 18.5 | 0.745 ± 0.077 |
| 14 |
|
Not a substrate | Not a substrate | Not a substrate | 19.0 ± 22.0 | 1120 ± 1360 | 1.81 ± 0.13 |
| Alkyl N-Methylpyrrolidinyl Thioesters & Esters | |||||||
| 15 |
|
48.6 ± 2.8 | 218 ± 16 | 22.3 ± 0.4 | 0.432 ± 0.020 | 103 ± 10 | 0.421 ± 0.024 |
| 16 |
|
82.8 ± 51.6 | 4580 ± 1560 | 1.68 ± 0.61 | 24.9 ± 7.4 | 8020 ± 3900 | 0.327 ± 0.055 |
| 17 |
|
80.8 ± 11.4 | 947 ± 134 | 8.53 ± 0.23 | 1.23 ± 0.03 | 174 ± 4 | 0.704 ± 0.019 |
| 18 |
|
112 ± 52 | 4680 ± 2200 | 2.43 ± 0.79 | 31.0 ± 6.3 | 3770 ± 1540 | 0.877 ± 0.243 |
| 19 |
|
Not a substrate | Not a substrate | Not a substrate | 6.63 ± 0.61 | 177 ± 27 | 3.78 ± 0.26 |
| 20 |
|
Not a substrate* | Not a substrate* | Not a substrate* | 6.88 ± 0.52 | 912 ± 85 | 0.758 ± 0.088 |
| 21 |
|
Not a substrate | Not a substrate | Not a substrate | 6.63 ± 0.10 | 52.7 ± 1.7 | 12.6 ± 0.2 |
| 22 |
|
Not a substrate* | Not a substrate* | Not a substrate* | 22.8 ± 13.0 | 1750 ± 774 | 1.24 ± 0.22 |
| Aryl N-Methylpyrrolidinyl Thioesters & Esters | |||||||
| 23 |
|
Not a substrate | Not a substrate | Not a substrate | 7.91 ± 0.16 | 21.7 ± 1.0 | 36.5 ± 1.9 |
| 24 |
|
Not a substrate | Not a substrate | Not a substrate | 0.706 ± 0.067 | 28.6 ± 5.1 | 2.49 ± 0.19 |
| 25 |
|
Not a substrate | Not a substrate | Not a substrate | 8.96 ± 0.48 | 84.6 ± 7.3 | 10.6 ± 0.4 |
| 26 |
|
Not a substrate | Not a substrate | Not a substrate | 13.2 ± 2.4 | 188 ± 47 | 7.12 ± 0.62 |
| 27 |
|
Not a substrate | Not a substrate | Not a substrate | 6.42 ± 0.09 | 22.9 ± 1.8 | 28.1 ± 1.8 |
| 28 |
|
Not a substrate | Not a substrate | Not a substrate | 8.50 ± 0.33 | 125 ± 6 | 6.79 ± 0.07 |
| 29 |
|
Not a substrate | Not a substrate | Not a substrate | 4.43 ± 0.71 | 123 ± 28 | 3.63 ± 0.29 |
| 30 |
|
Not a substrate | Not a substrate | Not a substrate | 133 ± 18 | 956 ± 138 | 14.0 ± 0.7 |
*To determine if a compound is a substrate, the kcat/Km value greater than or equal to that of the reporter molecule (2.62 × 106 (min−1 M−1) is required, which these compounds did not exhibit. Since the corresponding thioesters are not substrates, we conclude that these compounds are also not substrates.