Comet parameter: allowed_missed_cleavage
         
         - Number of allowed missed enzyme cleavages in a peptide.
         
- Parameter is not applied of the no-enzyme option is specified
         in the search_enzyme_number
         parameter.
         
- The default value is "2" if this parameter is missing.
         
Example:
         
allowed_missed_cleavage = 0     for no missed cleavages
         
allowed_missed_cleavage = 2     allow two missed cleavages