. 2020 Feb 3;10:1659. doi: 10.1038/s41598-020-57671-x

Table 2.

Kinetic parameters for recombinant jrPPO1-wt, the five investigated mutants and jrPPO1 purified from natural sources (previously published) with the monophenolic substrates tyramine and L-tyrosine and the diphenolic substrates dopamine and L-DOPA.

Enzyme/Mutant	tyramine			L-tyrosine
Enzyme/Mutant	k_cat (s⁻¹)	K_m (mM)	k_cat/K_m (s⁻¹ mM⁻¹)	k_cat (s⁻¹)	K_m (mM)	k_cat/K_m (s⁻¹ mM⁻¹)
jrPPO1-wt (recombinant)	24.7 ± 1.5	0.451 ± 0.084	55 ± 11	6.0 ± 1.1	1.42 ± 0.37	4.3 ± 1.4
Phe260Gly	0.323 ± 0.025	3.05 ± 0.72	0.103 ± 0.026	n.a.*	n.a.*	0.00783 ± 0.00049
Asn240Lys	0.0542 ± 0.0034	8.2 ± 1.4	0.0066 ± 0.0012	n.a.*	n.a.*
Leu244Arg	1.62 ± 0.09	2.68 ± 0.53	0.60 ± 0.12	n.a.*	n.a.*	0.624 ± 0.0068
Asn240Lys/Leu244Arg	n.a.	n.a.		n.a.	n.a.
Asn240Thr/Leu244Arg	n.a.	n.a.		n.a.	n.a.
jrPPO1 (natural source)	18.3²⁶	0.27²⁶		2.7²⁶–20.80³⁴	1.02²⁶–1.90³⁴
Enzyme/Mutant	dopamine			L-DOPA
jrPPO1-wt (recombinant)	92.5 ± 7.8	0.75 ± 0.13	123 ± 24	111.2 ± 8.8	6.2 ± 1.0	18.1 ± 3.4
Phe260Gly	7.36 ± 0.98	1.2 ± 0.4	5.9 ± 2.2	9.1 ± 1.6	10.5 ± 3.4	0.86 ± 0.32
Asn240Lys	2.51 ± 0.40	19.8 ± 4.7	0.132 ± 0.097	1.08 ± 0.15	16.7 ± 3.7	0.065 ± 0.017
Leu244Arg	24.9 ± 1.6	2.36 ± 0.41	10.6 ± 2.0	10.5 ± 1.2	4.2 ± 1.2	2.51 ± 0.78
Asn240Lys/Leu244Arg	0.029 ± 0.002	6.8 ± 1.3	0.00428 ± 0.00085	0.104 ± 0.019	16.5 ± 4.8	0.0060 ± 0.0021
Asn240Thr/Leu244Arg	0.789 ± 0.079	6.6 ± 1.5	0.122 ± 0.026	0.180 ± 0.027	13.1 ± 3.3	0.0129 ± 0.0040
jrPPO1 (natural source)				199.3³⁴	8.80³⁴

n.a. indicates substrate-enzyme combinations that showed no activity. n.a.* represents samples that were active but could not be measured due to extensively reduced reactivity and increased K_m values in combination with limited substrate solubility. Measurements were performed in triplicates. The numbers represent mean values ± one standard deviation.