TABLE 2.
Activity of some key enzymes involved in the synthesis of sugar nucleotide precursors of gluconacetan polymerizationa
| Enzyme (location) | Activityb of enzyme during growth on:
|
||
|---|---|---|---|
| Glucose | Sucrose | Fructose | |
| Levansucrase | |||
| Levan synthetase (medium) | 1,206 ± 56 | 970 ± 14 | 1,150 ± 21 |
| Levan synthetase (membrane) | 4,627 ± 275 | 24,432 ± 2,310 | 18,782 ± 3,960 |
| Levan synthetase (cytosol) | 20 ± 2 | 395 ± 45 | 138 ± 9 |
| Invertase (medium) | 15 ± 10 | 4 ± 3 | 0 ± 2 |
| Invertase (membrane) | 2,149 ± 407 | 6,627 ± 785 | 4,110 ± 660 |
| Invertase (cytosol) | 7 ± 5 | 290 ± 45 | 64 ± 5 |
| Glucose dehydrogenase (cytosol) | 0.80 ± 0.2 | 0.87 ± 0.2 | 0.42 ± 0.2 |
| Glucose-6-P isomerase (cytosol) | 941 ± 200 | 1,257 ± 200 | 1,435 ± 200 |
| Glucose-1-P thymidylyltransferase (cytosol) | 31 ± 5 | 37 ± 5 | 123 ± 5 |
| UDP-glucose pyrophosphorylase (cytosol) | 162 ± 100 | 210 ± 100 | 558 ± 100 |
| Mannose-6-P isomerase (cytosol) | 3 ± 1 | 3 ± 1 | 2 ± 1 |
a
Results are from analysis of samples that were collected from culture during broth growth on glucose, sucrose, or fructose.
b
Activity values are given in units per gram of total protein.