Age-related changes in the proteolytic enzymes of mammalian lens

A longitudinal study has been conducted on three exopeptidases which include an esterase, leucine aminopeptidase, and a triglycinopeptidase and two endopeptidases, a neutral protease and a proteinase or catheptic activity in bovine lenses. The esterase and leucine aminopeptidase behave similarily showing increased activities with aging. Triglycinopeptidase has a somewhat lower order of magnitude when compared to the other exopeptidases. The neutral protease shows initially high activity early in the developmental life period, whereas, the proteinase or catheptic activity indicates a continuous increase with aging. Data is also provided on enzymic activity in the different sections of the lens which include the combined anterior cortex and epithelium, lens nucleus, posterior cortex, and equatorial ring.