Intermolecular disulfide bonding of lens membrane proteins during human cataractogenesis.
Two-dimensional diagonal electrophoresis has been used to characterize intermolecular disulfide bonding of membrane proteins from lenses of cataractous and normal patients. A component of approximately 18,000 daltons, linked via intermolecular disulfide bonding, was found in membrane preparations from 10 of 17 cataracts studied. In comparison, membrane from only 1 of 12 normal lenses of approximately the same age range was found to contain intermolecular disulfide bonding of a component of similar molecular weight. Treatment of normal lens with the oxidizing agents cupric sulfate and 1,10-phenanthroline resulted in intermolecular disulfide bonding of the 18K component in a manner similar to that found in cataractous lenses. Together these results demonstrate that human cataractogenesis is many times accompanied by intermolecular disulfide bonding of a membrane component of 18K and suggest that this intermolecular bonding may be the result of the previously reported oxidative insult of the lens during human cataract formation.
D000328:Adult; D000368:Aged; D002386:Cataract / Q000378:metabolism*; D003300:Copper / Q000494:pharmacology; D019327:Copper Sulfate; D003459:Crystallins / Q000378:metabolism*; D004220:Disulfides / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D006801:Humans; D066298:In Vitro Techniques; D007908:Lens, Crystalline / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D008566:Membranes / Q000032:analysis / Q000378:metabolism; D008875:Middle Aged; D010618:Phenanthrolines / Q000494:pharmacology
D003459:Crystallins; D004220:Disulfides; D010618:Phenanthrolines; D003300:Copper; D019327:Copper Sulfate