Table 1.
Hydrogen peroxide generation by lens crystallin fractions and crystallin-derived peptides*
| Proteins / peptides (100 µg) | H2O2 generation (nM) |
|---|---|
| Total lens extract (43-45yrs.) | 5.7 + 0.9 |
| α-crystallin fraction | 11.3 + 1.2 |
| βH-crystallin fraction | 6.1 + 0.2 |
| βL-crystallin fraction | 7.5 + 0.2 |
| γ-crystallin fraction | 6.7 + 0.3 |
| Recombinant αA-crystallin | 0.5 + 0.0 |
| BSA | 0.2 + 0.0 |
| LMW peptides from trypsin-digested α-fraction | 208.1 + 6.4 |
| LMW peptides from trypsin-digested βH -fraction | 156.2 + 6.2 |
| LMW peptides from trypsin-digested βL -fraction | 184.4 + 7.9 |
| LMW peptides from trypsin-digested γ -fraction | 150.0 + 4.3 |
| LMW peptides from trypsin-digested αA-crystallin (recombinant) | 29.8 + 0.2 |
| LMW peptides from trypsin-digested BSA | 3.2 + 0.0 |
| αA66-80 | 127 ± 12 |
| αA66-80 (V72P) | 4.5 + 0.3 |
| αA66-80 (H79A) | 1.9+ 0.2 |
*
Human lens crystallin fractions and crystallin-derived low molecular weight (LMW) peptides (100 µg) were incubated in phosphate buffer at 37°C for 4 h. At the end of the incubation, the amount of H2O2 formed was estimated, as described in the methods section. The amount of generated H2O2 is the average of three independent measurements.