Profiling of lens protease involved in generation of αA-66-80 crystallin peptide using an internally quenched protease substrate

摘要: Proteins of lens fiber cells are prone to accumulate extensive post-translational modifications because very little protein turnover. Lens proteins degraded via the proteolytic systems into peptides, which subsequently hydrolyzed by downstream aminopeptidases. Inefficient degradation can lead accumulation fragments and subsequent aggregation. Previously we showed that αA-66-80 peptide its truncated products in aging cataract human lenses. These peptides interact with crystallins, causing crystallin aggregation precipitation. N- C-terminal-blocked have cleavage sites generate fragment were used test extracts for sequence-specific proteases extracts. An internally quenched fluorogenic substrate containing site a protease was designed, synthesized characterize protease(s) capable generating this bovine We show potential present also resistant hydrolysis aminopeptidases lenses they suppress other peptides. Failure complete these vivo their aggregation, may ultimately formation cataract.