Characterization of abnormal proteins in the soluble lens proteins of CatFraser mice.

The murine mutation CatFraser causes a cataract in both the mutant heterozygote (C/+) and mutant homozygote (C/C). Our previous electrophoretic studies detected, in the lenses of both mutant genotypes, several proteins which did not appear to be present in normal lenses. Here we show, using more sensitive methods, that traces of these proteins previously characterized as abnormal are in fact present in normal lenses. Furthermore, these proteins have a primary structure very similar to that of the alpha-crystallins. We conclude that the mutation accelerates the degradation of alpha-crystallin, which in the normal lens proceeds at a very slow rate.