Bovine lens multicatalytic proteinase complex.

The ocular lens grows by laying down new cells on top of old in a differentiation process that results in loss of protein-synthesizing capacity, but preservation of the cells themselves for the lifetime of the organism. The transparency and refractive index of the lens depend on protein integrity and longevity, yet proteolysis is needed for normal growth and development. Therefore, control of proteolysis must be stringent. Here we review the structural features and major proteolytic enzymes of the lens and the properties of the bovine lens multicatalytic proteinase complex, including native and SDS-PAGE patterns, and activation and inhibition by cations, amphiphilic molecules and temperature.