. 2023 Sep 12;13:15053. doi: 10.1038/s41598-023-41805-y

Table 4.

Summary of experimental results for the hydrolysis of nitrocefin by the P99 β-lactamase and comparison with the simulations.

% Substrate conversion^a	On the basis of Eq. (1) or (3)		On the basis of Eq. (4)		Ratios Eq. (1)/Eq. (4)
% Substrate conversion^a	(K_m)_app (µM)	V_app (µM min⁻¹)	K_m (µM)	V (µM min⁻¹)	(K_m)_app/K_m	V_app/V
25	39.4 ± 5.0	36.2 ± 2.2	32.4 ± 4.0	34.3 ± 2.3	1.22 ± 0.15 (exp: 1.20)^b	1.06 ± 0.07 (exp: 1.05)^b
50	49 ± 2.7	37 ± 1.3	29 ± 4	33 ± 1.3	1.66 ± 0.10 (exp: 1.54)^b	1.12 ± 0.04 (exp: 1.12)^b
60	55.5 ± 5.8	39.2 ± 2.3	28.5 ± 3.0	31.5 ± 2.0	1.95 ± 0.22 (exp: 1.81)^b	1.24 ± 0.07 (exp: 1.18)^b

Since the reaction time-courses had been continuously monitored, quasi-initial rates could also be determined (at 5 and 10% substrate conversion). Analysis of these data with the HW linearisation yielded the following results: at 5% conversion, V = 35 ± 2.3 µM min⁻¹ and K_m = 35 ± 7 µM; at 10% conversion, V = 34 ± 2.2 µM min⁻¹ and K_m = 35 ± 5 µM.

^aAt the lowest [S]₀ value.

^bExpected on the basis of Table 1.