Table 3. Kinetic parameters for hydrolysis of substrates 9–16 by recombinant human renin, increase of fluorescence intensities and quenching efficiencies.

Hydrolysis conditions: 50 mM Mops/NaOH, pH 7.0, 2 mM EDTA, 0.5% BSA, 0.1% NaN₃ and 1% DMSO at 37 °C. Fluorescence was measured at excitation and emission wavelengths of 328 nm and 388 nm respectively. q.e., quenching efficiency.

Substrate	kcat/Km (M−1·s−1)*	F1/F0	q.e. (%)	kcat (s−1)†	Km (μM)†
9	352000	16	94	1.90	5.50
10	111000	10	90	0.14	1.24
11	117000	12	92	0.15	1.94
12	43000	6	83	0.12	2.96
13	108000	7	86	0.26	3.40
14	108000	7	86	0.27	2.94
15	No hydrolysis	−	−	−	−
16	122000	7	86	0.55	3.70

* Determined via the progress-curve method under pseudo-first-order conditions.

† Determined via the initial-rate method.