Table 3.
Rates of reductive PP sequences, measured by NADH oxidation, in reactions catalysed by spinach SEP with a variety of sugar phosphates as substrates
| Substrate | Concentration (mM) | Rate of NADH oxidation (μmol h−1 mg−1 Chl) | |
|---|---|---|---|
| Spinacha | Peab | ||
| Ru 1,5-P2 | 2.0 | 592 ± 79 (9) | 546 |
| Rib 5-P | 2.0 | 743 ± 92 (10) | 453 |
| Rib 5-P | 0.2 | 366 ± 39 (10) | – |
| Seh 7-P | 2.0 | 183 ± 32 (12) | 184 |
| Seh 1,7-P2 | 2.0 | 76 ± 14 (10) | 112 |
| Fru 1,6-P2 | 2.0 | 10.1 ± 2.7 (10) | 74.1 |
| Fru 1,6-P2 | 1.0 | 18.2 ± 2.9 (11) | – |
| Fru 6-P | 2.0 | 1.0c ± 0.3 (13) | 77.6 |
| Fru 6-P + DHAP | 2.0/0.20 | 1.8 ± 0.4 (10) | 142 |
| Fru 6-P + PGA | 2.0/0.20 | 2.9 ± 0.4 (8) | – |
| DHAP | 2.0 | 13.1 ± 3.1 (10) | 53 |
| DHAP | 0.20 | 5.0 ± 1.4 (11) | 22.6 |
| Ara 5-P | 2.0 | 1.1 (9)d | – |
| d-g-d-i-oct 1,8-P2 | 2.0 | 3.7 ± 1.7 (5) | – |
| d-g-d-a-oct 1,8-P2 | 2.0 | 9.3 ± 1.5 (6) | – |
| d-g-d-i-oct 8-P | 2.0 | 6.3 ± 2.4 (5) | – |
| d-g-d-a-oct 8-P | 2.0 | 8.2 ± 3.0 (5) | – |
a Shows the results of this study. Results are mean values ± standard deviation. The number of determinations using different batches of SEP are shown in brackets
b Shows the data of Furbank and Lilley (1981) for peas
c When preparations were made using sonicated spinach chloroplast suspensions and Fru 6-P as substrate, varying (non-reproducible) rates up to 5 μmol h−1 mg−1 Chl were recorded
d Results were variable with different SEP batches, three of the SEP preparations with Ara 5-P did not support any NADH oxidation