TABLE 2.
ABE-I alanine-substituted thrombin mutants have impaired catalysis for the OPN-(162–197) peptide
The specificity constant kcat/Km was estimated for the hydrolysis of OPN-(162–197) peptide by WT and selected mutant thrombins under first order rate conditions in assay buffer fixed at 145 mm NaCl. Values for the mean ± S.E. are based on at least two assays performed in duplicate.
| Thrombin | Location | kcat/Km | WT activity |
|---|---|---|---|
| mm-1s-1 | % | ||
| WT | 16.35 ± 0.58 | 100 | |
| K65A | ABE-I | 5.38 ± 1.25 | 33 |
| H66A | 2.87 ± 0.41 | 18 | |
| R68A | 5.80 ± 0.32 | 35 | |
| Y71A | 3.76 ± 0.01 | 23 | |
| R73A | 7.41 ± 0.19 | 45 | |
| R89A/R93A/E94A | ABE-II | 7.13 ± 0.40 | 44 |
| R98A | 15.10 ± 0.83 | 92 | |
| E169A/K174A/D175A | 14.79 ± 1.23 | 90 | |
| R178A/R180A/D183A | 16.33 ± 0.35 | 100 |