TABLE 7.
Effect of NaCl on the hydrolysis of HHL and Z-FHL synthetic peptides by ACE constructs
All values were obtained from chloride-titrated activity assays. Units for SAmin and SAmax are milliunits·μg−1, and Kd(app) values are in mm. Data shown represent the average of two independent determinations, each in triplicate. The approximation symbol indicates that accurate estimates of Kd(app) and SAmax could not be obtained because the chloride concentration range was insufficient for saturation to occur. SAmax for these values is activity at 500 and 50 mm NaCl for HHL and Z-FHL, respectively.
| Construct | HHL |
Z-FHL |
||||||
|---|---|---|---|---|---|---|---|---|
| Kd(app) | SAmin | SAmax | SAmin % of SAmax | Kd(app) | SAmin | SAmax | SAmin % of SAmax | |
| mm | milliunits/μg | milliunits/μg | % | mm | milliunits/μg | milliunits/μg | % | |
| N-domain | 0.2 | 10.5 | 24.2 | 43.5 | 0.8 | 36.5 | 206.7 | 17.6 |
| C-domain | 46.9 | 2.1 | 83.2 | 2.5 | 1.8 | 93.5 | 339.3 | 27.5 |
| R186H | 76.9 | 3.7 | 113.3 | 3.2 | 2.1 | 130.3 | 467.2 | 27.8 |
| E403R | 2.7 | 6.3 | 99.8 | 6.3 | 0.3 | 214.5 | 398.5 | 53.8 |
| D465T | 12.7 | 0.4 | 46.6 | 0.8 | 2.8 | 2.1 | 110.7 | 1.8 |
| R522K | ∼339.7 | 4.1 | ∼10.0 | 40.5 | ∼104.6 | 97.2 | ∼193.2 | 50.3 |
| R522Q | ∼417.8 | 4.6 | ∼11.2 | 40.8 | ∼231.9 | 161.9 | ∼218.0 | 74.3 |