Substrate Specificity of Acidic and Neutral Sialidases Obtained From Human Erythrocyte Membranes
| Substrate . | Apparent Vmax ( μU/mg protein) . | |
|---|---|---|
| . | Acidic Sialidase . | Neutral Sialidase . |
| Ganglioside | ||
| GD1a | 170 | 420 |
| GM3 (+0.1% Triton CF-54) | 380 | 650 |
| Glycoprotein | ||
| Fetuin | ND | 24.8 |
| α1-Acidic glycoprotein | ND | 29.8 |
| Transferrin | ND | 28.0 |
| Oligosaccharide | ||
| α-2-3 Sialyllactose | 37.1 | 33.0 |
| Artificial substrate | ||
| MU-NeuAc | 104 | 66.6 |
| Substrate . | Apparent Vmax ( μU/mg protein) . | |
|---|---|---|
| . | Acidic Sialidase . | Neutral Sialidase . |
| Ganglioside | ||
| GD1a | 170 | 420 |
| GM3 (+0.1% Triton CF-54) | 380 | 650 |
| Glycoprotein | ||
| Fetuin | ND | 24.8 |
| α1-Acidic glycoprotein | ND | 29.8 |
| Transferrin | ND | 28.0 |
| Oligosaccharide | ||
| α-2-3 Sialyllactose | 37.1 | 33.0 |
| Artificial substrate | ||
| MU-NeuAc | 104 | 66.6 |
Enzyme source of acidic sialidase was supernatant obtained after exhaustive PIPLC treatment of resealed vesicles and centrifugation. Enzyme source of neutral sialidase was pellet obtained after exhaustive PIPLC treatment of resealed vesicles and centrifugation. For details, see Materials and Methods. The data are the mean values of five experiments ± SD values.
Abbreviation: ND, not detectable.