TABLE 1.
Functional characterization of the pike silverside (C. estor) desaturases Fads2a and Fads2b in S. cerevisiae
| Conversion (%) | ||||
| FA Substrate | FA Product | Fads2a | Fads2b | Activity |
| 18:3n-3 | 18:4n-3 | 0 | 56.5 | Δ6 |
| 18:2n-6 | 18:3n-6 | 0 | 25.2 | Δ6 |
| 20:3n-3 | 20:4n-3 | 0 | 12.2a | Δ8 |
| 20:2n-6 | 20:3n-6 | 0 | 9.9a | Δ8 |
| 20:4n-3 | 20:5n-3 | 3.3 | 25.8 | Δ5 |
| 20:3n-6 | 20:4n-6 | 0 | 11.6 | Δ5 |
| 22:5n-3 | 22:6n-3 | 28.9 | 0 | Δ4 |
| 22:4n-6 | 22:5n-6 | 10.3 | 0 | Δ4 |
Yeast S. cerevisiae were transformed with pYES2-fadsa and pYES2-fadsb and grown in the presence of Δ6 (18:3n-3 and 18:2n-6), Δ8 (20:3n-3 and 20:2n-6), Δ5 (20:4n-3 and 20:3n-6), and Δ4 (22:5n-3 and 22:4n-6) FA substrates. Conversions were calculated according to the formula [individual product area/(all products areas + substrate area)] × 100.
Conversions of Δ8 substrates (20:3n-3 and 20:2n-6) by Fads2b include stepwise reactions due to multifunctional desaturation abilities. Thus, the conversions of the C. estor Fads2b on 20:3n-3 and 20:2n-6 include the Δ8 desaturation toward 20:4n-3 and 20:3n-6, respectively, and their subsequent Δ5 desaturations to 20:5n-3 and 20:4n-6, respectively.