Distribution of Fluorescence in the Human Cataractous Lens

Normal and cataractous lenses contain a highly fluorescent yellow protein which is insoluble in water but soluble in 7 m urea containing 0.01 m mercaptoethanol. The amount of this protein increases with the development of cataracts and this is accompanied by a decrease in the water-soluble protein content of the lens. The protein has a molecular weight of over 80,000 in the presence of 7 m urea and mercaptoethanol. It appears to be a derivative of the sub-units of the soluble crystalline cross-linked through covalent bonds other than disulphide bonds.