PROTEIN CLEAVAGE SITES IN EXPERIMENTAL CATARACTOUS LENSE

    Project: Research project

    Description

    Cataracts are the third leading cause of blindness in the United
    States. However, the underlying biochemical mechanisms of most
    cataracts are unknown. One alteration in lenses that may
    contribute to cataract formation is accumulation of partially
    degraded protein fragments. Many experimental cataracts studied
    to date contain significant amounts of partially degraded lens
    proteins. The role these proteins play in cataract formation and
    which lens proteases are responsible for protein degradation are
    unknown. The two goals of this project are to better understand the
    significance of proteolysis in cataractous lenses, and to determine
    which endogenous lens proteases are activated during cataract
    formation. Partially degraded lens proteins, from selenite and
    galactose induced cataracts and rom hereditary mouse cataracts,
    will be isolated by electrophoresis. These partially degraded
    polypeptides will be analyzed using protein micro-sequencing
    techniques to identify their origin, and to determine their N - and
    C-terminal cleavage sites. Intact lens proteins will then be
    incubated in vitro with three different major lens endopeptidases
    (high molecular neutral protease complex, trypsin-like protease,
    and calpain II). The cleavage sites occurring in vitro will be
    compared to cleavage sites occurring in vivo during cataract
    formation. Endopeptidase cleaved lens proteins will also be
    incubated with two major lens exopeptidases (aminopeptidase III and
    leucine aminopeptidase). This will determine if endopeptidase
    cleavage makes lens proteins better substrates for exopeptidases. Proteolysis may contribute to cataract formation by significantly
    altering the properties of lens proteins. Comparison of in vivo
    cleavage sites found in cataractous lenses with cleavage sites
    produced by proteases in vitro may identify the proteases that are
    activated in the lens. Determining which lens proteases are active
    during experimental cataract formation may suggest ways of treating
    human cataract. For instance, inhibitors of proteases could be
    used as therapeutic agents to slow the progression of cataract.
    StatusFinished
    Effective start/end date4/1/897/31/16

    Funding

    • National Institutes of Health
    • National Institutes of Health: $256,452.00
    • National Institutes of Health: $148,706.00
    • National Institutes of Health: $92,500.00
    • National Institutes of Health: $261,685.00
    • National Institutes of Health: $213,750.00
    • National Institutes of Health: $142,490.00
    • National Institutes of Health: $346,500.00
    • National Institutes of Health
    • National Institutes of Health: $188,750.00
    • National Institutes of Health
    • National Institutes of Health: $76,016.00
    • National Institutes of Health
    • National Institutes of Health: $339,570.00
    • National Institutes of Health: $294,382.00
    • National Institutes of Health: $85,595.00
    • National Institutes of Health: $188,750.00
    • National Institutes of Health: $329,175.00
    • National Institutes of Health: $188,750.00
    • National Institutes of Health
    • National Institutes of Health: $346,500.00
    • National Institutes of Health: $259,068.00
    • National Institutes of Health: $261,401.00

    Fingerprint

    Lenses
    Crystallins
    Cataract
    Proteins
    Peptide Hydrolases
    Proteolysis
    Post Translational Protein Processing
    Water
    Exopeptidases
    beta-Crystallins
    Endopeptidases
    Mass Spectrometry
    Electrophoresis
    Light
    Calpain

    ASJC

    • Medicine(all)