Proline Isomerase References



 Hello all!
     I was wondering if there are any references which affirm or disprove the
 following idea:
     Proline isomerases, because they make proline unstable by isomerizing it
 between the trans
     and cis conformation, can exhibit a protolytic effect (i.e., cause the break
 down of
     proline-rich proteins).
 Does anyone know if this is "true", or the correct (or more
 appropriate) forum to
 ask this question in?
     Thanks,
             Ray Crawford.