Table 1. Summary of enzyme kinetic of MDH and ICDH from E. coli and S. salinarum.
Salt or Osmolyte (M) |
Km (mM) |
Vmax (U mg−1) |
Specifity Constant (U mg−1 mM−1) |
Osmolyte Performance (Vmax/Km relative to 0.05 M NaCl) |
|
---|---|---|---|---|---|
MDHE.coli | 0.05 M NaCl | 0.022 | 1,486 | 67,443 | 100 |
1.2 M NaCl | 0.163 | 227 | 1,393 | 2.1 | |
2.4 M NaCl | 0.26 | 78 | 306 | 0.5 | |
2.5 M GB | 0.018 | 273 | 15,478 | 23 | |
MDHS.salinarum | 0.05 M NaCl | 0.038 | 2,062 | 54,832 | 100 |
1.2 M NaCl | 0.20 | 314 | 1,568 | 3 | |
2.4 M NaCl | 0.25 | 144 | 578 | 1.1 | |
2.5 M GB | 0.031 | 519 | 16,527 | 30 | |
ICDHE.coli | 0.05 M NaCl | 0.021 | 46 | 2,167 | 100 |
1.2 M NaCl | 1.2 | 12.3 | 10 | 0.5 | |
2.4 M NaCl | 3.9 | 4.7 | 1.2 | 0.1 | |
2.5 M GB | 0.009 | 3.2 | 369 | 17 | |
ICDHS.salinarum | 0.05 M NaCl | 0.019 | 6.8 | 353 | 100 |
1.2 M NaCl | 0.68 | 1.6 | 2.3 | 0.7 | |
2.4 M NaCl | 0.82 | 0.32 | 0.4 | 0.1 | |
2.5 M GB | 0.014 | 2.4 | 170 | 48 |
GB, glycine betaine; ICDH, isocitrate dehydrogenase; MDH, malate dehydrogenase; NaCl, sodium chloride.