Preferential interaction of alpha crystallin with denatured forms of gamma crystallin.

PURPOSE To characterize the possible interaction of alpha crystallin with partially denatured forms of gamma crystallin. METHODS Gamma crystallin was denatured in the presence of guanidine hydrochloride, then dialyzed in the presence or absence of alpha crystallin. The high-molecular-weight complex formed in the presence of alpha was characterized by gel filtration chromatography, electron microscopy, and quantitative Western blot analysis. RESULTS Relative to native alpha or reconstituted aggregates of purified alpha, the higher molecular weight complex possessed a greater mean diameter and contained increased amounts of gamma crystallin. CONCLUSIONS Alpha crystallin preferentially interacts with partially denatured forms of a lens protein, consistent with its putative role as a functional molecular chaperone in the intact lens.