TABLE 2.

Kinetic parameters of SADS‐CoV PLP2 wild type and mutants with different fluorescent substrates

Substrate	Kinetic parameter	PLP2 (WT)	ΔN49	C101A	H256A	D269A	F83A	D96A	D98A	W102A	N99A	Y257A
Z‐KAGG‐AMC	kcat (min−1)	0.92	2.18	0.0000	0.0000	0.0000	0.0000	0.0000	0.7047	0.0000	0.4388	0.5158
	Km (μM)	8.79	17.57	0.0000	0.0000	0.0000	0.0000	0.0000	35.600	0.0000	28.000	31.990
	kcat/Km (μM−1 min−1)	0.104 ± 0.017	0.124 ± 0.0116	0.0000	0.0000	0.0000	0.0000	0.0000	0.0198 ± 0.003	0.0000	0.0157 ± 0.002	0.0161 ± 0.003
Z‐LRGG‐AMC	kcat (min−1)	0.6871	1.0180	0.0000	0.0000	0.7341	0.5095	0.0000	0.0925	0.1858	0.0000	0.2332
	Km (μM)	37.340	42.0500	0.0000	0.0000	44.170	17.7700	0.0000	19.140	28.1700	0.0000	16.650
	kcat/Km (μM−1 min−1)	0.0184 ± 0.003	0.0242 ± 0.004	0.0000	0.0000	0.0166 ± 0.002	0.0287 ± 0.004	0.0000	0.0048 ± 0.001	0.0066 ± 0.001	0.0000	0.0140 ± 0.003
Ub‐AMC	kcat (min−1)	1.2850	1.5050	0.0000	0.5957	0.5396	2.1230	0.0000	0.0000	NA	NA	NA
	Km (μM)	0.3416	0.3206	0.0000	0.4732	0.3692	0.4532	0.0000	0.0000	NA	NA	NA
	kcat/Km (μM−1 min−1)	3.76 ± 0.45	4.69 ± 0.8	0.0000	1.25 ± 0.48	1.46 ± 0.38	4.68 ± 0.50	0.0000	0.0000	NA	NA	NA
ISG15‐AMC	kcat (min−1)	3.9330	5.3680	0.0000	2.5180	NA	NA	NA	NA	NA	NA	NA
	Km (μM)	0.6199	0.6467	0.0000	0.6308	NA	NA	NA	NA	NA	NA	NA
	kcat/Km (μM−1 min−1)	6.3 ± 0.2	8.3 ± 0.1	0.0000	3.9 ± 0.11	NA	NA	NA	NA	NA	NA	NA

Abbreviation: NA, not available.