Table 1. Curve Fitting Results for the Pyruvate C=O Stretch Profile in the LDH Michaelis Complexesa.
| band (cm–1) | fwhm (cm–1) | intensity | population (%) | frequency average (cm–1) | |
|---|---|---|---|---|---|
| pyruvate | 1708 | 22 | 22 | 100 | 1708 |
| [13C/15N](D168N)LDH·NADH·pyruvate | 1683 | 5.2 | 2.2 | 17.9 | |
| 1691 | 7.2 | 6.7 | 54.5 | ||
| 1701 | 13.2 | 3.4 | 27.6 | 1692.3 | |
| 1708 | 22 | 7.1 | unbound | ||
| LDH·NADH·pyruvate | 1673 | 5.7 | 6.5 | 33.3 | |
| 1679 | 5.0 | 4.7 | 24.1 | ||
| 1686 | 7.9 | 5.7 | 29.2 | ||
| 1699 | 13 | 2.6 | 13.3 | 1681.7 | |
| [13C/15N]LDH·NADH·pyruvate | 1674 | 5.1 | 1.2 | 10.8 | |
| 1679 | 5.9 | 7.9 | 71.2 | ||
| 1686 | 4.7 | 1.5 | 13.5 | ||
| 1703 | 5.7 | 0.49 | 4.42 | 1680.5 |
a
Band represents the observed C=O stretch frequency. The resolution of the spectrometer was 2 cm–1. The frequency errors for most bands are ±2 cm–1 but for bands between 1670 and 1675 cm–1 are ±3 cm–1. fwhm denotes the full line width at the half-maximum. Intensity denotes the band intensity (arbitrary units). Population denotes the percentage of bound pyruvate at the given frequency. Frequency average denotes the population-weighted average frequency of all bound pyruvate bands.