TABLE 4.

Pyruvate synthesis (reverse reaction)

Reaction componentsaNADPH oxidation (nmol/min)Sp act (units/mg protein)b
PFORFqrB
Complete15.4 ± 20.055 ± 0.0073 ± 0.5
    −NADPH000
    −FqrB000
    −PFOR5.90.0211.2
    −FldA4.70.0170.9
    −Acetyl-CoA6.40.0231.3
    −CO26.20.0221.2
Corrected valuec90.0321.8
  • a Complete reverse reaction under pseudoanaerobic conditions was monitored following the oxidation of NADPH in presence of 1 μM Fld, 0.3 mg/ml PFOR, and 5 μg/ml Fqr. Formation of reduced CoA from acetyl-CoA was demonstrated during the reaction (Fig. 5). The activities were computed in the absence of one component of the reaction (−). Some residual activity remains as long as FqrB, NADPH, and some electron acceptor remain in the reaction. This electron acceptor likely could be residual oxygen in the sample.

  • b The specific activity (Units) for each protein (PFOR or FqrB) is in μmol min−1 mg protein−1.

  • c Initial velocities were corrected for residual oxidase activity.