Decreased molecular chaperone property of alpha-crystallins due to posttranslational modifications.

We studied the effect of oxidation, mixed disulfide formation and glycation of alpha-crystallins on their molecular chaperone property. The ability of alpha-crystallins to protect heat-induced denaturation and aggregation of beta L-crystallin was significantly diminished by these modifications. alpha-Crystallin from senile human lenses also showed significant loss of chaperone-like property. Age-dependent increase in posttranslationally modified alpha-crystallins is the likely cause for this change.