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. 2000 Mar 7;97(6):2480–2485. doi: 10.1073/pnas.040559797

Table 1.

Summary of the characterization of reconstituted l-lactate oxidase with FMN analogs

No. Substituted group Hammett parameter
Absorption peak
Midpoint potential
Reduction by l-lactate
Reduction by l-mandelate
Oxidation by O2
Reaction with sulfite
σpara σortho Σσ Free, nm Bound, nm Free, mV Bound, mV kred, s−1 Kd, mM KIE kred, s−1 Kd, mM KIE kox, s−1⋅M−1 kon, s−1⋅M−1 koff, s−1
1 8-CN- +0.66 −0.06 +0.60 454 464 −50 +47 714 0.55 1.7 12.2 0.38 4.3 2.76  × 104 5.1 × 105 5.0 × 10−4
2 8-Cl- +0.23 −0.06 +0.17 442 454 −152 −65 600 0.42 0.270 0.35 5.01  × 105 4.3 × 105 8.7 × 10−3
3 8-H- +0.00 −0.06 −0.06 448 460 −180 −110 726 0.51 0.051 0.28 8.01  × 105 4.0 × 105 0.020
4 8-H-,6-CH3- +0.00 −0.12 −0.12 452 464 −198 −142 263 1.20 0.045 1.00 1.56  × 104
5 8-CH3S- +0.00 −0.06 −0.06 476 492 −204 −151 220 62 0.019 11 9.22  × 105 1,020 0.3  
6 8-CH3- −0.17 −0.06 −0.23 448 457 −207 −128 320 1.00 4.6 0.038 0.64 3.8 1.84  × 106 1.5 × 105 0.076
7 8-(CH3)2N- −0.83 −0.06 −0.89 505 509 −246 −220 2.17 245 1.98  × 106 17.6 0.93 
8 6-O- −0.17 −0.25* −0.42* 428 426 −255 −270 0.038 97 1.96  × 104
9 6-NH2- −0.17 −0.34 −0.51 428 444 −278 −217 8.71 4.06 1.20  × 105
10 8-S- −0.53* −0.06 −0.59* 520 600 −290 −224 0.026 0.12 1.26  × 106 45
11 8-NH2- −0.66 −0.06 −0.72 480 482 −310 −255 1.76 1.63 >3 3.58  × 106 1,230 2.2  
12 8-O- −0.81 −0.06 −0.87 475 485 −331 −318 <10−3 1.62  × 106 2 0.36 

KIE, the kinetic isotope effect. 

*Average value between neutral and anionic form.