TABLE 2.
Catalytic activity of aldose reductase with propanal conjugates
The enzyme activity was measured at the substrate concentration of 1 mm and is expressed as nmol of NADPH oxidized/min/mg of protein. Values are the mean ± S. E. NA: no activity.
| Substrate | m/z | Activity |
|---|---|---|
| Glyceraldehyde | 124 ± 6 | |
| Carnosine-propanal (β-Ala-His-propanal or propanal-β-Ala-His) | 283 | 113 ± 10 |
| FDP-carnosine or propanal-cycloimine | 321 | 20 ± 2 |
| Anserine-propanal (β-Ala-Me-His-propanal or propanal-β-Ala-Me-His) | 297 | 21 ± 1 |
| FDP-anserine or propanal-Me-cycloimine | 335 | 23 ± 4 |
| Homocarnosine-propanal (Me-β-Ala-His-propanal or propanal-Me-Ala-His) | 297 | 79 ± 7 |
| FDP-Homocarnosine or propanal-cyclo-methylimine | 335 (NA) | |
| Pyridoxamine propanal | 225 | 140 ± 9 |
| FDP-pyridoxamine | 263 | 35 ± 2 |
| Hydralazine-propanal | 273 | 13 ± 1 |
| FDP-hydralazine | 199 | 10 ± 1 |
| Aminoguanidine-propanal | 169 | 10 ± 2 |
| FDP-Aminoguanidine | 187 | 16 ± 1 |