TABLE 4.
In vitro substrate range of purified pyruvate:alanine aminotransferasesa
| Substrate class | Substrate | % conversion by PP_0596 | % conversion by PP_2180 | % conversion by PP_5182 |
|---|---|---|---|---|
| Polyamines | 1,3 diaminopropane | 65 ± 0.9% | 95 ± 0.7% | 96 ± 3.5% |
| putrescine | 2 ± 0.7% | 109 ± 1.4% | 112 ± 1.8% | |
| cadaverine | 9 ± 4.2% | 97 ± 1.8% | 103 ± 8.5% | |
| 1,6 diaminohexane | 14 ± 1.5% | 85 ± 4% | 88 ± 0.6% | |
| spermidine | 101 ± 1.1% | 105 ± 5.8% | 112 ± 1.2% | |
| ω-amino acids | β-alanine | 51 ± 0.5% | NA | NA |
| γ-aminobutyric acid | 75 ± 2% | 76 ± 1.5% | 83 ± 4.2% | |
| 5-aminovaleric acid | 70 ± 2.5% | 71 ± 1.4% | 73 ± 0.9% | |
| 6-aminocaproic acid | 78 ± 1.9% | 82 ± 0.8% | 84 ± 1% | |
| GABA isomers | dl-2-aminobutyric | 55 ± 1.3% | 95 ± 1.2% | 100 ± 5.6% |
| 3-aminobutyric acid | 87 ± 3.1% | 12 ± 1.6% | 16 ± 3.8% | |
| dl-3-aminoisobutyric | 70 ± 2.4% | 6 ± 1.3% | 12 ± 2.5% | |
| Proteinogenic amino acids | l-isoleucine | NA | NA | 1 ± 0.5% |
| l-leucine | NA | 5 ± 0.7% | NA | |
| l-lysine | 59 ± 49.4% | 61 ± 3.8% | 65 ± 4.9% | |
| l-valine | NA | NA | NA |
a
Tested substrates were added in excess to pyruvate. Activity of the aminotransferases on the tested substrates was measured indirectly through the quantification of the co-product alanine. Percent conversion is relative to the expected measurement of alanine if the amine acceptor pyruvate was completely transformed. Error represents the standard deviation of three replicates. NA indicates that no activity was statistically detected above controls.