Table 3.
Secretion and activity of tryptophan mutants against tributyrina
| Colipase | Expression | Activity ± SD | Colipase | Expression | Activity ± SD |
|---|---|---|---|---|---|
|
| |||||
| μg/ml | U/mg | μg/ml | U/mg | ||
| Wild-type | 15.6 ± 2.1 | 12675 ± 227 | I57W | 1.9 ± 0.5 | 8760 ± 251 |
| L16W | ND | ND | Y59W | 17.7 ± 2.0 | 12435 ± 210 |
| L34W | 13.3 ± 1.5 | 13955 ± 159 | I75W | 10.8 ± 1.3 | 12915 ± 291 |
| L36W | 5.9 ± 1.1 | 12515 ± 193 | V76W | 14.0 ± 1.7 | 12775 ± 210 |
| L54W | 1.9 ± 0.7 | 12655 ± 277 | I79W | 12.7 ± 1.6 | 13550 ± 246 |
| Y55W | 18.4 ± 1.9 | 13110 ± 290 | F84W | 15.4 ± 1.8 | 12810 ± 118 |
a
Recombinan colipase was expressed in P. pastoris. The colipase function in the medium was measured in the standard pH-stat assay using tributyrin in 4 mM NaTDC. The amount of colipase in the medium was calculated from the specific activity of the purified colipase. Mean ± S.D. is given.