Characterization of disulfide-linked crystallins associated with human cataractous lens membranes

In order to characterize possible disulfide-linked interactions between lens fiber cell membranes and crystallins, two-dimensional diagonal electrophoresis has been used in combination with Western blot analysis. When these blots were probed with monospecific antisera against alpha, beta and gamma crystallins, membrane from five individual normal lenses showed no disulfide-bonded components. Membrane from 13 individual cataractous human lenses showed no disulfide-bonded alpha crystallin, but did show significant amounts of disulfide-bonded beta crystallin in four out of the 13 lenses studied, and significant amounts of disulfide-bonded gamma crystallin in 10 out of the 13 lenses studied. Together, these studies demonstrate that intermolecular disulfide bonding of crystallins to purified fiber cell membranes is found only in cataractous lenses, and that the predominant polypeptide species involved in this interaction is gamma crystallin.