Quantitation of membrane-associated crystallins from aging and cataractous human lenses

Membrane from individual cataractous and normal human lenses has been prepared by discontinuous sucrose gradient centrifugation. A sensitive solid-phase radioimmunoassay has been developed to quantitate the levels of alpha, beta, and gamma crystallins associated with membrane obtained from each sucrose gradient interface. The results of this analysis demonstrate significant levels of all three crystallins associated with purified membrane. Although the relative percentage of each membrane-associated crystallin does not change during aging and/or cataractogenesis of the human lens, membrane from cataractous lenses in characterized by greater total amounts of crystallins associated with purified membrane obtained from denser interfaces of the discontinuous sucrose gradient.