Ascorbate, Fe3+, or Cu2+ and oxygen induced the oxidation of bovine lens crystallins. The modifications mimicked those that occur in the lens with aging. The modifications included the formation of nondisulfide crosslinks in α- and βH-crystallin and the cleavage of α-, βH-, and the low molecular weight crystallin fractions. In all three fractions, there was a loss of the more basic protein species and an increase in the more acidic species. Nontryptophan fluorescence with emission spectra between 400 and 500 nm was produced in βH-crystallin. Cu2+ was less effective than Fe3+ in catalyzing the modification of βH-and γ-crystallin. Both metal ions were equally effective in catalyzing the modification of α-crystallin.
ASJC Scopus subject areas
- Molecular Biology