Table 1.
Summary of kinetic constants determined in this work
| Substrate | [Half-saturation], nM | kcat,app, min−1 | Cooperativity coefficient |
|---|---|---|---|
| Wild-type 208-12 arrays | 33.6 ± 5.0 | 1.42 ± 0.15 | 1.97 ± 0.15 |
| Single H3 tail arrays | 79.5 ± 9.2 | 1.54 ± 0.12 | 0.86 ± 0.13 |
| His6-tagged H3 arrays | 36.2 ± 2.9 | 1.48 ± 0.04 | 1.86 ± 0.07 |
| Wild-type 196-1 monos | 17.3 ± 4.9 | 1.02 ± 0.11 | 1.76 ± 0.17 |
| H3 tail-swap monos | 85.7 ± 5.7 | 0.84 ± 0.06 | 1.02 ± 0.07 |
| Tetra-Ala H3/WT H3 monos | 38.9 ± 6.9 | 1.07 ± 0.07 | 0.95 ± 0.03 |
| Tetra-Ac H3/WT H3 monos | 11.5 ± 2.4 | 1.12 ± 0.08 | 0.99 ± 0.10 |
| H3 tail peptide | 130,000 | 0.52 | 0.97 |
Kinetic constants were determined from the average of three independent trials, except with the H3 tail peptide, which was the average of two trials. Half-saturation concentration was calculated from K1/n. The apparent turnover rate constant, kcat,app, was determined from Vmax/[E]0 and reflects an initial concentration of acetyl-CoA of 4.0 μM. For the H3 tail peptide, in which [acetyl-CoA]0 is 10.0 μM, the apparent turnover rate constant has been normalized to be directly comparable with the other assay.