refine, potential modification mass


The value of this parameter is an ASCII string, of the format M1@X1,M2@X2,..., Mn@Xn

where Mi is a floating point number (potential modification mass in Daltons) and Xi is a single letter abbreviation for a type of amino acid residue.


  1. No error is produced if a non-standard amino acid abbreviation is used.
  2. If a residue type is listed more than once, the last instance of the residue is used to set the modification.
  3. Both positive and negative potential modification masses may be used.


The format of this parameter is the same as the residue, potential modification mass parameter. See this discussion of this parameter for a general explanation of its meaning and use. The value for the refine version of this parameter is used to create a longer, more comprehensive list of relatively rare potential modifications. The value of the use potential modifications for full refinement parameter controls which steps in the refinement use this parameter.

see also: residue, potential modification mass | refine | refine, use potential modifications for full refinement

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