TABLE 4.
[3H]Methylation of both l-histidine and various l-histidine-containing peptides catalyzed by UPF0586 proteins of various species
The reaction of methyl group transfer from SAM into the indicated methyl group acceptors was determined with the use of homogeneous recombinant rat, human, chicken, or yeast UPF0586 proteins. Enzyme preparations (0.20–0.72 μg of protein) were incubated for 10 min at 30 °C (yeast) or 40 °C (vertebrates) in the presence of 1 μm [1H + 3H]SAM (100 pmol, ∼400 × 103 cpm) and a 10 mm concentration of the indicated methyl group acceptor. Values are the means ± S.E. of 3–9 separate experiments. ND, not determined; activity below the detection limit.
| Methyl group acceptor | UPF0586 protein |
|||
|---|---|---|---|---|
| Rat | Human | Chicken | Yeast | |
| pmol min−1 mg−1 | pmol min−1 mg−1 | pmol min−1 mg−1 | pmol min−1 mg−1 | |
| β-Ala-His (carnosine) | 1934 ± 58 | 1124 ± 33 | 1236 ± 36 | 2268 ± 73 |
| GABA-His (homocarnosine) | 1209 ± 44 | 567 ± 9 | 562 ± 47 | 1110 ± 90 |
| α-Ala-His | 404 ± 44 | 122 ± 7 | 134 ± 4 | 252 ± 110 |
| l-Histidine | 75 ± 17 | 172 ± 96 | 16 ± 10 | 99 ± 68 |
| Gly-His | 1802 ± 198 | 1047 ± 38 | 1080 ± 65 | 1696 ± 135 |
| Gly-Gly-His | 1993 ± 5 | 1044 ± 13 | 1102 ± 10 | 1449 ± 100 |
| Gly-His-Gly | 73 ± 21 | 9 ± 5 | 22 ± 10 | 155 ± 89 |
| His-Gly | 28 ± 4 | ND | 5 ± 5 | 144 ± 72 |
| His-α-Ala | 6 ± 6 | 11 ± 11 | 4 ± 4 | 33 ± 31 |
| β-Ala-N-π-methyl-His (anserine) | ND | 48 ± 27 | 9 ± 9 | 74 ± 58 |