Cytoskeletal proteins of the aging human lens.

The cytoskeletal proteins of the human lens were studied by SDS-PAGE, 2-D electrophoresis and immunologically. Spectrin, vimentin and actin were identified in the superficial fiber cells of human lenses even to age 87 years. These proteins are lost from the deeper cortical and nuclear fiber cells, where a broad zone of acidic protein (36-42 Kd) emerges even in the transparent normal lens. Age-related changes in the water-soluble fraction include the increased prominence of proteins of 56 Kd and 36 Kd in the cortex, and of 38 Kd in the nucleus.