TABLE IV.
pKa values and Hill coefficients of titratable residues in OMTKY3 in the high pH region.
| pKa | Hill coefficient | |||||
|---|---|---|---|---|---|---|
| Titratable residue | PHREM | PHMD | Expt. | PHREM | PHMD | Expt. |
| NT-Leu | 6.7 (0.4) | 6.6 (0.4) | 8.0 | 0.96 (0.14) | 1.61 (0.93) | 0.88 |
| 6.7 (0.4) | 6.7 (0.4) | 0.84 (0.18) | 0.81 (1.22) | |||
| 6.7 (0.1) | 6.7 (0.2) | 0.86 (0.11) | 0.93 (0.15) | |||
| Tyr11 | 13.8 (4.8) | - | 10.2 | 0.39 (0.38) | - | 0.73 |
| 13.1 (4.9) | - | 0.10 (0.48) | - | |||
| 12.6 (0.5) | - | 2.29 (0.26) | - | |||
| Lys13 | 12.0 (1.2) | 11.7 (0.8) | 9.9 | 0.93 (0.34) | 22.39 (38.89) | 0.69 |
| 11.9 (1.2) | 12.0 (0.8) | 0.44 (0.60) | 0.48 (44.64) | |||
| 12.0 (0.2) | 11.6 (0.2) | 0.59 (0.07) | 0.78 (0.09) | |||
| Tyr20 | 11.5 (0.2) | 11.8 (0.3) | 11.1 | 0.78 (0.08) | 1.03 (0.20) | 0.57 |
| 11.5 (0.2) | 11.8 (0.3) | 0.75 (0.09) | 0.87 (0.26) | |||
| 11.5 (0.1) | 11.7 (0.1) | 0.74 (0.05) | 0.84 (0.08) | |||
| Lys29 | 12.5 (0.6) | 12.6 (0.5) | 11.1 | 0.82 (0.12) | 4.88 (3.15) | 0.87 |
| 12.5 (0.6) | 12.6 (0.5) | 0.65 (0.20) | 1.04 (4.97) | |||
| 12.4 (0.1) | 12.5 (0.2) | 0.72 (0.08) | 1.01 (0.23) | |||
| Tyr31 | - | - | >12.5 | - | - | - |
| - | - | - | - | |||
| 17.0 (2.0) | 19.9 (16.2) | 0.35 (0.14) | −10.0 (7.9) | |||
| Lys34 | 10.3 (1.4) | 10.5 (1.4) | 10.1 | 0.69 (0.19) | 1.80 (1.85) | 0.66 |
| 10.4 (1.4) | 10.6 (1.4) | 0.36 (0.38) | 0.38 (2.33) | |||
| 10.4 (0.2) | 10.4 (0.2) | 0.45 (0.04) | 0.63 (0.06) | |||
| His52 | 7.5 (0.2) | 7.4 (0.2) | 7.5 | 0.93 (0.09) | 1.09 (0.25) | 0.93 |
| 7.5 (0.2) | 7.4 (0.2) | 0.89 (0.09) | 0.91 (0.31) | |||
| 7.5 (0.1) | 7.5 (0.1) | 0.90 (0.08) | 0.92 (0.09) | |||
| Lys55 | 10.8 (0.1) | 10.7 (0.1) | 11.1 | 0.83 (0.08) | 0.85 (0.10) | 0.64 |
| 10.8 (0.1) | 10.7 (0.1) | 0.82 (0.08) | 0.81 (0.11) | |||
| 10.8 (0.1) | 10.8 (0.1) | 0.84 (0.06) | 0.84 (0.07) | |||
Upper, middle and lower values for each residue are calculated with Method I, Method II and Method III, respectively. Estimated errors are indicated in the brackets.