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Table 3 Changes in enzyme activities following PQ stressa

From: A systematic investigation of Escherichia coli central carbon metabolism in response to superoxide stress

Enzymes Metabolic
steps
Activity
normal conditions
Activity
paraquat treated
PQ/normal Ratios
IDH icd 0.301 ± 0.009 0.155 ± 0.010 0.51
AKGDH akd 0.191 ± 0.008 0.090 ± 0.015 0.47
MDH mdh 0.106 ± 0.003 0.303 ± 0.013 2.86
G6PDH gdh 0.428 ± 0.000 1.219 ± 0.011 2.85
PGI hxi 0.207 ± 0.003 0.297 ± 0.007 1.44
ICL gs1 0.787 ± 0.012 1.506 ± 0.004 1.91
ENO eno 0.072 ± 0.012 0.072 ± 0.013 1.00
THD - 0.122 ± 0.005 0.181 ± 0.003 1.48
  1. aEnzyme activities in cell extracts of control or paraquat-treated wildtype E. coli JM101 grown on glucose at D = 0.17 h-1 under aerobic chemostat conditions. Ratio calculation was based on control conditions (wildtype aerobic growth on glucose). The unit of enzyme activity is μmol min-1 (mg protein) -1. All measurements were performed in triplicate. Data are expressed as means ± S.D. IDH: isocitrate dehydrogenase NADP-dependent, AKGDH: α-ketoglutaric acid dehydrogenase, PGI: glucose phosphate isomerase, MDH: malate dehydrogenase, G6PDH: glucose-6-phosphate dehydrogenase, ICL: isocitrate lyase, ENO: enolase, THD: transhydrogenase.