Presence of low molecular weight polypeptides in human brunescent cataracts

Microdissected sections from opaque & brunescent lens nuclei contain low molecular weight (4,000-8,000 dalton) polypeptides not found in microdissected sections of transparent lens nuclei. Tryptic digestion of these polypeptides from different cataracts reveal similar peptide maps. Together, these results support the involvement of proteolysis in human cataractogenesis, and suggest the possibility of similar molecular mechanisms occurring in cleavage of lens polypeptides during formation of the opaque & brunescent human cataract.