Comet

Comet parameter: variable_N_terminus_distance

• This parameter affects how the variable_N_terminus parameter is applied.
• The variable modification on the n-terminus can be applied to
  • all peptides analyzed by entering a value of -1
  • only peptides containing the protein's n-terminus by entering a value of 0
  • any positive integer N will have the program consider modifications on the n-terminus and the next N residues (effectively the first N+1 residues).
• The default value is "-1" if this parameter is missing.

Example:
variable_N_terminus_distance = -1   Applied to all peptides
variable_N_terminus_distance = 0     Applied only to peptides containing protein's n-terminus
variable_N_terminus_distance = 1     Applied on any peptide who's n-terminus is one of first 2 residues (n-term & next 1)
variable_N_terminus_distance = 12   Applied on any peptide who's n-terminus is one of first 13 residues (n-term & next 12)