TABLE 2.
Steady state kinetic parameters of BoGT6a in comparison with human GTA and bovine α3GT
| Parameter | GTAa | α3GTb | BoGT6ac |
|---|---|---|---|
| Donor substrate | UDP-GalNAc | UDP-Gal | UDP-GalNAc |
| Transferase activity | |||
| Ka (μm) | 13 | 430 | 335 ± 46 |
| Kb (μm) | 15 | 19 × 103 | 1170 ± 150 |
| Kia (μm) | 5 | 140 | 67 ± 5 |
| kcat (s−1) | 4.9 | 6.4 | 38 ± 3.8 |
| Hydrolase activity | |||
| Ka (μm) | NDd | 100 | 97 |
| kcat (s−1) | ND | 0.016 | 0.024 |
a Data reported by Seto et al. (29), measured in the presence of 20 mm Mn2+. The acceptor substrate was Fucα(1–2)Galβ-O-(CH2)7-CH3.
b Determined with lactose as substrate at 10 mm Mn2+ (10).
c Assays conducted using 2′-fucosyllactose as acceptor substrate in the presence of 10 mm EDTA.
d ND, not determined.