Table 4.
Equilibrium dissociation constant (KD) values determined for wildtype and Y43A and Y43R mutant SPINK1 inhibitors against nonsulfated and sulfated human cationic trypsins
| KD (pM) | Hu1 (Escherichia coli) | Hu1-SO4 (native) |
|---|---|---|
| SPINK1 wildtype | 1.1 ± 0.4 | 67.4 ± 7.7 |
| SPINK1 Y43A | 20.3 ± 2.5 | 62.2 ± 5.6 |
| SPINK1 Y43R | 103.8 ± 13.9 | 27.1 ± 2.3 |
Hu1, nonsulfated human cationic trypsin purified from E. coli; Hu1-SO4, native sulfated human cationic trypsin purified from pancreatic juice.
Measurements were carried out as described under Experimental procedures section. Data from three experiments were fitted globally. The error of the fit is indicated.