Table 2. Enzyme/substrate specificity of the MpILR1 and MpILR1L244S auxin hydrolases.
All hydrolase values are expressed as picomoles of auxin released per minute per milliliter (averages from four to seven replicate experiments) plus or minus the se. Untransformed E. coli (NovaBlue) cells were employed as negative hydrolysis controls. Positive hydrolysis is indicated by boldface values. IBA and IPA are indole butyric acid and indole proprionic acid, respectively. The comparative data for Medicago, loblolly pine, and Arabidopsis are from Campanella et al. (2008, 2014) and LeClere et al. (2002), respectively. Note that the data from LeClere et al. (2002) were expressed as nanomoles of auxin released per minute per milligram of protein. N/A indicates the data is not available.
| Substrate | MpILR1 | MpILR1L244S | PtIAR31 | MtIAR34 | AtILL2 |
|---|---|---|---|---|---|
| IAA-Asp | 0.00 ± 0.00 | 0.00 ± 0.00 | 220 ± 50.0 | 500 ± 123 | 62 |
| IAA-Ala | 0.00 ± 0.00 | 0.00 ± 0.00 | 20 ± 3.0 | 50 ± 13 | 1,600 |
| IAA-Ile | 0.00 ± 0.00 | 16.53 ± 6.65 | 0.00 ± 0.00 | 0.00 ± 0.00 | 67 |
| IAA-Leu | 10.20 ± 5.10 | 16.23+6.29 | 0.00 ± 0.00 | 70 ± 18 | 120 |
| IAA-Phe | 0.00 ± 0.00 | 0.00 ± 0.00 | 70 ± 10.0 | 0.00 ± 0.00 | 170 |
| IAA-Val | 0.00 ± 0.00 | 0.00 ± 0.00 | <1.0 | 20 ± 3 | 96 |
| IAA-Gly | 0.00 ± 0.00 | 0.00 ± 0.00 | 150 ± 30.1 | 30 ± 5 | 46 |
| IBA-Ala | 0.00 ± 0.00 | 744.58 ± 134.87 | 1,930 ± 10.0 | 270 ± 29 | N/A |
| IPA-Ala | 1.66 ± 1.65 | 18.32 ± 16.69 | N/A | N/A | N/A |