Table 1.
Acceptor substrate specificity of the β3GnT enzyme
| Acceptors | pmol/min/mg prot added
|
|
|---|---|---|
| Sf9 mock* | β3GnT† | |
| UDP–GlcNAc‡ | ||
| Gal(β1–4)GlcNAc(β1–OpNP) | 6 | 1,478 |
| Gal(β1–4)Glc(β1–OBn) | 4 | 1,034 |
| Gal(β1–4)GlcNAc(octyl) | 5 | 284 |
| Gal(β1–3)GlcNAc(octyl) | 5 | 8 |
| Gal(β1–3)GalNAc(octyl) | 5 | 4 |
| Gal(α1–OpNP) | 4 | 89 |
| Gal(β1–OpNP) | 4 | 26 |
| GalNAc(α1–OBn) | 4 | 5 |
| GalNAc(β1–OBn) | 5 | 6 |
| GlcNAc(α1–OBn) | 4 | 4 |
| GlcNAc(β1–OBn) | 11 | 7 |
| GlcNAc(β1–3)GalNAc(α1–OBn) | 8 | 5 |
| Gal(β1–4)Glc | 13 | 502 |
| Gal(β1–4)GlcNAc | 14 | 714 |
| Lac-N-neo-tetraose§ | 14 | 748 |
| Lac-N-tetraose§ | 13 | 45 |
| UDP–Gal‡ | ||
| GalNAc(α1–OBn) | 170 | 190 |
| GalNAc(β1–OBn) | 15 | 18 |
| GlcNAc(α1–OBn) | 11 | 10 |
| GlcNAc(β1–OBn) | 23 | 22 |
| UDP–GalNAc‡ | ||
| Gal(α1–OpNP) | 3 | 5 |
| Gal(β1–OpNP) | 3 | 5 |
| GlcNAc(α1–OBn) | 3 | 3 |
| GlcNAc(β1–OBn) | 27 | 31 |
All acceptors were assayed at 5 mM except the (Mco)-derivatized acceptors, which were assayed at 2 mM.
*
Lysate of Sf9 cells infected with a wild-type baculovirus.
†
Lysate of Sf9 cells infected with a recombinant baculovirus expressing the human β3GnT enzyme.
‡
Carbohydrate donor.
§
Lac-N-neo-tetraose, Gal(β1–4)GlcNAc(β1–3)Gal(β1–4)Glc; Lac-N-tetraose, Gal(β1–3)GlcNAc(β1–3)Gal(β1–4)Glc