Table 7.
Substrate specificity of PDAT in microsomal preparations from developing (middle-stage) sunflower and safflower seeds
| pmol [14C]TAG formed/min × mg protein | |||||
|---|---|---|---|---|---|
| Substrates: 5 nmol sn1, sn2-di-18:1-DAG + 5 nmol of [14C]phospholipid indicated below | |||||
| PC; sn1-18:1- sn2-[14C]18:0 | PC; sn1-18:1- sn2-[14C]18:1 | PC; sn1-18:1- sn2-[14C]18:2 | PC; sn1-[14C]18:1-sn2-18:1 | PE; sn1-18:1- sn2-[14C]18:1 | PE; sn1-18:1- sn2-[14C]18:2 |
| Plant | |||||
| Sunflower | |||||
| 23 ± 3 (55) | 42 ± 3 (100) | 75 ± 8 (179) | 10 ± 2 (24) | 85 ± 2 (202) | 163 ± 13 (388) |
| Safflower | |||||
| 27 ± 2 (47) | 57 ± 12 (100) | 205 ± 8 (360) | 12 ± 3 (21) | 122 ± 15 (214) | 417 ± 75 (732) |
Mean ± SD shown (n ≥ 3); figures in parentheses show relative PDAT activity (activity towards sn1-18:1-sn2-[14C]18:1-PC was treated as 100 %)