Table 1.
Substrate specificity of AEOMT in crude extracts of loblolly pine xylem and yeast, and antibody inhibition of AEOMT activity
| Substrate | Loblolly pine xylem extracts
|
Yeast recombinant AEOMT
|
Loblolloy pine xylem extracts + antibody
|
Yeast recombinant AEOMT + antibody
|
||||
|---|---|---|---|---|---|---|---|---|
| Spec. act. | Rel. act. | Spec. act. | Rel. act. | Spec. act. | % inhibition | Spec. act. | % inhibition | |
| Caffeic acid | 441 ± 37 | 100 | 310 ± 32 | 100 | 317 ± 40 | 28 | 214 ± 15 | 31 |
| 5-Hydroxyferulic acid | 346 ± 25 | 78 | 235 ± 26 | 76 | 286 ± 16 | 17 | 198 ± 24 | 16 |
| Caffeoyl CoA | 755 ± 33 | 171 | 268 ± 28 | 86 | 446 ± 32 | 41 | 105 ± 3 | 61 |
| 5-Hydroxyferuloyl CoA | 657 ± 31 | 149 | 210 ± 12 | 68 | 331 ± 24 | 50 | 95 ± 13 | 55 |
Spec. act., specific activity (in pmol/min/mg); Rel. Act., relative activity (in %). The specific activities were mean ± SD (n = 6 independent assays). Crude extract protein (7 μg) was incubated with antiserum or preimmune antiserum (14 μg of protein) for 10 min at room temperature before addition of enzyme assay components. Preimmune serum had no effect on AEOMT activity. All controls used boiled protein extracts.