Schiff's base formation in the lens protein gamma-crystallin.
Uniquely among the soluble lens-specific proteins, gamma-crystallin is capable of binding the strongly chromophoric aldehyde retinal. A role for gamma-crystallin in protecting lens components from toxic aldehydes resulting from membrane oxidation is proposed and a molecular model of the probable interaction site is presented. The sequence of a tetrapeptide at this site is identical to that of the retinal binding site of bacteriorhodopsin.