Two-dimensional gel analysis of chick lens proteins.

Two-dimensional analyses of the chick lens water-soluble and water-insoluble proteins were conducted according to the method of O'Farrell (1975). The results define the isoelectric properties of the water-soluble and the urea-soluble polypeptides and demonstrate differences in composition for cortical and nuclear proteins. Chick lens vimentin consists of at least two isoelectric variants, and its breakdown products were identified. Chick lens actin is primarily of the gamma-type. The 47 K polypeptide specific for fiber cells shows considerable charge heterogeneity, and its most acidic component is found primarily in the nuclear fiber cells. This study also shows that apparently single bands resolved by one-dimensional SDS-polyacrylamide gel electrophoresis of the urea-soluble fraction consists of different proteins, and that the composition of such bands may further be altered by ph. This is especially relevant to the composition of the 47 and 50 K bands.