Table 2.
Substrate specificity analysis
| ST3Gal-I | ST3Gal-II | ST3Gal-III | ST3Gal-IV | ST3Gal-VI | |
|---|---|---|---|---|---|
| Acceptor | Conversion (%dpm/μl) | ||||
| Type-I | |||||
| Galβ1,3GlcNAcβ1,3lac-β-pNp [1] | 0.47 | 8.75 | 59.9 | 19.2 | 7.62 |
| MeO-2-Galβ1,3GlcNAc-OBn [1a] | Nil | Nil | 32.88 | 5.91 | 4.53 |
|
| |||||
| Type-II | |||||
| Galβ1,4GlcNAcβ1,3Gal-β-pNp [2] | - | - | 16.78 | 79.5 | 5.4 |
| Galβ1,4GlcNAcβ1,3Galβ1,4GlcNAc-pNp [2a] | - | - | 15.21 | 20.87 | 13.14 |
| MeO-4-Galβ1,4GlcNAc-OBn [2b] | - | - | 15.56 | 66.97 | 100* |
| Galβ1,4GlcNAcβ1,6(4FGalβ1,3)GalNAc-OBn [2c] | - | - | 100* | 100* | 35.1 |
|
| |||||
| Type-III | |||||
| Galβ1,3GalNAc-OBn [3] | 100* | 100* | - | - | - |
| MeO-3-Galβ1,3GalNAc-OBn [3a] | Nil | Nil | - | - | - |
| Galβ1,3(GlcNAcβ1,6)GalNAc-OBn [4] | 48.53 | 100 | - | - | - |
Conversion quantified as % transfer of radioactivity from CMP-[14C]Neu5Ac to acceptors.
*
Data normalized to the acceptor exhibiting maximum activity for that enzyme, set as 100%. Nil: Conversion < 3×background.