The parameter can have the values yes or no.
- No error message is generated when an uninterpretable value is entered for this parameter.
- If no value is set, the default value is no.
X! TANDEM uses a process called "refinement" to improve the speed and accuracy of
peptide modelling. When the parameter value is yes, then the refinement
process is used, otherwise X! TANDEM functions like other sequence modelling engines.
The algorithm used by Tandem is an example of possible algorithms that belong
to this class of methods for obtaining similar results. Variations
of the scheme may be necessary to adequately capture all of the
details of specific experimental protocols. The steps in a simple
refinement-based identification/modeling process are as follows:
- Match a set of tandem mass spectra containing a large set of spectra against a list of proteins, with a small value for the number of missed cleavages (e.g., 0 or 1) and a limited selection of potential modifications and create a set of protein sequences that are most likely to contain valid matches to the spectra (e.g., all proteins containing peptides with an expectation value < 0.1);
- Match the tandem spectra against the new, smaller list of protein sequences, using a large value for the number of missed cleavages and a large selection of potential modifications; and
- If desired, perform the same matching procedure as step 2, using nonspecific
see also: GPM refinement
X! TANDEM API description project