TABLE 2.
Kinetic parameters obtained from the Fre-luciferase coupled assay
Reactions were initiated with the rapid injection of buffer containing 100 mm Na+/K+ phosphate and 100 mm NaCl, pH 7.0.
| Flavin substrate | Light intensitya | Relative light intensity | Km coupledb | Km uncoupledc |
|---|---|---|---|---|
| (1011 × q·s-1) | μm | μm | ||
| FMN | 250 | 1 | 0.9 | 2.2 |
| Riboflavin | 7 | 0.028 | 1.3 | 2.5 |
a
Values determined 5 s after initiation of the reaction.
b
Michaelis constants were determined with different flavin concentrations, 1 μm Fre oxidoreductase, 10 mm decanal, and 10 μm NADPH and 5 μm luciferase. Values based upon plots of velocity measured by light output versus flavin concentration.
c
Taken from spectroscopic measurements previously reported (36).