Blue-fluorescent bovine alpha-crystallin.

Blue-fluorescent alpha-crystallin has been isolated from bovine lenses by gel-filtration on Sephacryl S-200 Superfine. The blue fluorescence of this alpha-crystallin is characterized by fluorescence peaks at about 410 and 435 nm and two excitation peaks at about 350 and 370 nm. This finding suggests the existence of two different blue-fluorescences in bovine alpha-crystallin. Both low molecular weight alpha-crystallin and higher molecular weight alpha-crystallin exhibit similar blue fluorescence. With aging, in the nuclear region of bovine lenses, blue fluorescent low molecular weight alpha-crystallin shifts to non-covalently-linked higher molecular weight aggregates which are also blue-fluorescent.