Table 2.
Kinetic analysis of AtGH3.15 using indoles with varied side-chain length
Steady-state kinetic parameters were determined for IAA, IPA, and IBA as described under “Experimental procedures.” With IVA, saturation was not observed (maximum [S] = 250 μm), and an estimate of catalytic efficiency based on linear slope of initial velocity (if Km ≫ [S], then v = kcat/Km) is noted. Assays were performed with varied concentrations of the indole compound (0–10 mm), 1 mm ATP, and 10 mm glutamine. Average values ± S.D. (n = 3) are shown. Data were fit to the Michaelis–Menten equation using SigmaPlot. IPA, indole-3-propionic acid.
| Indole compound (side-chain length) | kcat | Km | kcat/Km |
|---|---|---|---|
| min−1 | μm | m−1 s−1 | |
| IAA (C2) | 0.76 ± 0.09 | 556 ± 160 | 23 |
| IPA (C3) | 10.2 ± 0.5 | 3,430 ± 360 | 50 |
| IBA (C4) | 9.9 ± 0.2 | 527 ± 43 | 313 |
| IVA (C5) | ∼540 |