Table 1. Kinetic constants of AKR1B15, AKR1B10 and AKR1B1 with aldehydes and ketones.
| Substrate | AKR1B15 | AKR1B10 | AKR1B1 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Km (μM) | k cat (min−1) | k cat/Km (mM−1·min−1) | Km (μM) | k cat (min−1) | k cat/Km (mM−1·min−1) | Km (μM) | k cat (min−1) | k cat/Km (mM−1·min−1) | |
| Carbohydrate aldehydes | |||||||||
| d,l-glyceraldehyde | 880 | 10.7 | 12.4 | 6,000 a | 35 a | 6 a | 50 a | 31 a | 660 a |
| Aromatic aldehydes | |||||||||
| pyridine-3-aldehyde | 2.9 | 9 | 3,150 | 13 b | 150 b | 12,000 b | 10 b | 61 b | 6,100 b |
| benzaldehyde | <1* | 12.1 | >12,100 | 9.7 b | 104 b | 11,000 b | 21 b | 91 b | 4,300 b |
| cinnamaldehyde | <1* | 13.3 | >13,300 | 34.7 | 240 | 6,900 | 31 | 29 | 950 |
| Alkanals | |||||||||
| hexanal | 3.1 | 7.3 | 2,300 | 112 b | 142 b | 1,300 b | 5 b | 28 b | 5,600 b |
| Alkenals | |||||||||
| acrolein | 36 | 8.8 | 240 | 110 c | 116 c | 1,070 c | 884 c | 11 c | 12 c |
| trans-2-hexenal | 5 | 11.3 | 2,200 | 28 b | 49 b | 1,700 b | 9 b | 16 b | 1,800 b |
| 4-hydroxy-2-nonenal | 2.2 | 5.2 | 2,500 | 31 c | 121 c | 3,900 c | 716 c | 50 c | 70 c |
| citral | 1.5 | 5.5 | 3,700 | 4.5 | 35 | 7,400 | 35 | 68 | 1,750 |
| farnesal | <1* | 4.8 | >4,800 | 2.3 b | 30 b | 13,000 b | 37 b | 27 b | 700 b |
| Ketones | |||||||||
| 2-butanone | 780 | 10.5 | 13.5 | LA | LA | ||||
| 3-buten-2-one | 21.3 | 8.2 | 380 | LA | LA | ||||
| 3-nonen-2-one | 1.7 | 6.76 | 4,000 | LA | LA | ||||
| 2-cyclohexen-1-one | 365 | 4.41 | 12.1 | LA | LA | ||||
| α-Dicarbonyls | |||||||||
| 2,3-butanedione | <1* | 10.6 | >10,600 | 540 d | 260 d | 480 d | 110 d | 23 d | 210 d |
| 2,3-hexanedione | <1* | 9.5 | >9,500 | 51 b | 79 b | 1,500 b | 17 b | 49 b | 2,900 b |
| β-Dicarbonyls | |||||||||
| 2,4-pentanedione | 40 | 2.2 | 55 | 58,900 | 8.6 | 0.15 | 8,100 | 16.7 | 2.2 |
| 3,5-heptanedione | 1,300 | 5.3 | 3.9 | >50,000 | - | - | 12,000 | 26 | 2.2 |
| Cofactor | |||||||||
| NADPH | 5.7 | 10 | 2.9 e | ||||||
Enzymatic activity was measured spectrophotometrically. For the determination of the kinetic parameters for NADPH, 3 and 60 mM d,l-glyceraldehyde was used with AKR1B15 and AKR1B10, respectively. LA, low activity (≤ 10 mU/mg) was detected at saturating concentration of substrate for AKR1B15; ND, not determined.
*Because of very low Km value, data are only approximate.
aData from [23].
bData from [66].
cData from [67].
dData from [68].
eData from [69].