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Table 1 Kinetic constants ( K m , μM; k cat , s -1 ; and k cat / K m , s -1 .mM -1 ) for the nine PODs from the P. ostreatus genome a

From: Ligninolytic peroxidase genes in the oyster mushroom genome: heterologous expression, molecular structure, catalytic and stability properties, and lignin-degrading ability

Substrate Kinetic constants VP1 VP2 VP3 MnP1b MnP2 MnP3 MnP4 MnP5 MnP6
VA K m 5,500 ± 46 10,400 ± 133 5,500 ± 100 -c - - - - -
k cat 12.7 ± 0.5 4.4 ± 0.2 1.7 ± 0.1 0 0 0 0 0 0
kcat/Km 2.3 ± 0.2 0.4 ± 0 0.3 ± 0 0 0 0 0 0 0
RB5 K m 5.4 ± 0.2 9.6 ± 1.8 1.2 ± 0.2 - - - - - -
k cat 12.9 ± 0.3 20.3 ± 2 1.2 ± 0.1 0 0 0 0 0 0
kcat/Km 2,380 ± 50 2,120 ± 175 990 ± 150 0 0 0 0 0 0
ABTS e K m 605 ± 81 (4.0 ± 0.4) 3,260 ± 363 (12 ± 1.6) 726 ± 30 (nsd) 111 ± 18 1,150 ± 38 778 ± 103 1,560 ± 76 455 ± 69 1,020 ± 80
k cat 126 ± 5 (14.4 ± 0.4) 209 ± 12 (8.7 ± 0.4) 328 ± 17 (ns) 90 ± 8 175 ± 3 222 ± 15 128 ± 3 53 ± 3 115 ± 5
kcat/Km 209 ± 21 (3,600 ± 20) 64 ± 4 (725 ± 36) 452 ± 10 (407 ± 12) 803 ± 7 152 ± 3 285 ± 19 82 ± 3 110 ± 10 112 ± 4
DMP e K m 45,100 ± 3,600 (54 ± 4) 18,900 ± 2,070 (607 ± 57) 108,000 ± 13,000 (51 ± 14) - 63,300 ± 12,800 59,100 ± 6,800 ns ns 117,000 ± 18,000
k cat 98 ± 4 (6.6 ± 0.1) 92 ± 5 (17 ± 0.6) 311 ± 0.4 (2.9 ± 0.2) 0 109 ± 14 101 ± 7.2 ns ns 56 ± 6
kcat/Km 2.2 ± 0.1 (122 ± 7) 4.9 ± 0 (28 ± 1) 2.9 ± 0.1 (57 ± 2) 0 1.7 ± 0.1 1.7 ± 0 0.4 ± 0 0.4 ± 0 0.5 ± 0
Mn 2+ K m 98 ± 5.6 18 ± 2 45 ± 3 7 ± 1 92 ± 5 101 ± 12 88 ± 4 22 ± 2 73 ± 9
k cat 185 ± 2.6 79 ± 2 172 ± 2 9 ± 0 159 ± 3 163 ± 5 125 ± 2 41 ± 1 109 ± 3
kcat/Km 1,900 ± 90 4,510 ± 412 3,930 ± 210 1,200 ± 80 1,730 ± 71 1,610 ± 170 1,410 ± 60 1,930 ± 170 1,500 ± 100
H 2 O 2 K m 64.6 ± 6.7 42.5 ± 1.4 220 ± 16 530 ± 92 66.7 ± 11.7 136 ± 7.5 85.6 ± 7.6 27.6 ± 1.2 22.8 ± 4.4
kcat/Km 1,750 ± 150 1,880 ± 40 2,410 ± 140 372 ± 54 3,680 ± 470 3,070 ± 130 3,040 ± 210 3,130 ± 110 3,280 ± 490
  1. aMeans and 95% confidence limits are shown; bdescribed as MnP [21], changed to VP because of the putative catalytic tryptophan [17], and renamed now as MnP1 because of its inability to oxidize high redox potential substrates; cdashes correspond to undetermined Km values when no activity was detected (kcat 0); dns, Km, and kcat not determined because of non-saturation (but kcat/Km determined from slope of observed activity versus concentration); eABTS and DMP oxidation by VPs showed biphasic kinetics providing a second set of constants (parenthesis) characterized by lower Km values (see Materials and methods section of Kinetic constants on selected substrates). ABTS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate; DMP, 2,6-dimethoxyphenol; MnP, manganese peroxidase; POD, class II peroxidase from the superfamily of non-animal (plant-fungal-prokaryotic) peroxidases; RB5, Reactive Black 5; VA, veratryl alcohol; VP, versatile peroxidase.