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 SA_min and SA_max are milliunits·μg⁻¹, and K_d(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 K_d(app) and SA_max could not be obtained because the chloride concentration range was insufficient for saturation to occur. SA_max 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