Table 4. Effect of citrate and NAD+/pyruvate on the diameters of human LDH-A association forms estimated by DLS experiments.
| Sample | Diameter (nm) | Area (%) |
|---|---|---|
| Control pH 7.5 8 µM LDH (Holo) |
10.96 (T) | 42.4 |
| 9.25 (D) | 45.9 | |
| 7.98 (M) | 12.0 | |
| Control pH 6.5 8 µM LDH (Holo) |
11.25 (T) | 5.7 |
| 9.14 (D) | 94.6 | |
| Control pH 5.0 8 µM LDH (Holo) |
9.52 (D) | 73.9 |
| 8.40 (M) | 26.5 | |
| Citrate pH 7.5 8 µM LDH (Holo) |
10.07 (T) | 40.3 |
| 9.27 (D) | 56.9 | |
| 8.40 (M) | 2.9 | |
| Citrate pH 6.5 8 µM LDH (Holo) |
10.45 (T) | 45.6 |
| 9.04 (D) | 42.3 | |
| 8.00 M) | 12.7 | |
| Citrate pH 5.0 8 µM LDH (Holo) |
10.32 (T) | 13.2 |
| 9.36 (D) | 37.6 | |
| 8.72 (M) | 49.4 | |
| NAD/Pyr pH 7.5 8 µM LDH (Holo) |
9.84 (T) | 57.2 |
| 8.82 (D) | 32.2 | |
| 7.97 (M) | 10.8 | |
| NAD/Pyr pH 6.5 8 µM LDH (Holo) |
9.35 (D) | 72.0 |
| 8.39 (M) | 29.0 | |
| NAD/Pyr pH 5.0 8 µM LDH (Holo) |
10.32 (T) | 24.2 |
| 9.02 (D) | 76.3 |
The distribution of the enzyme ensemble among different association forms was evaluated at the indicated pH values with LDH-A solutions supplemented with 2.5 mM citrate or with NAD+/pyruvate (2.5 and 0.5 mM, respectively). Control samples devoid of any additive were also analyzed. T, D, and M indicate the assignment of a detected component to enzyme tetramer, dimer, and monomer, respectively. In addition to the estimated diameters, the area of each component is also indicated.