Search parameters (2024.01)
Comet search parameters are defined here. These are valid for Comet version 2024.01.X.
Parameters for all versions of Comet can be found here. Entries marked with an * are new parameters. Entries marked with an ** are modified parameters.
To generate a comet.params file appropriate for your Comet binary, issue the command “comet -p”.
Example comet.params files (primary differences are the MS and MS/MS mass tolerance settings):
- comet.params.low-low for low res MS1 and low res MS2 e.g. ion trap
- comet.params.high-low high res MS1 and low res MS2 e.g. Velos-Orbitrap
- comet.params.high-high high res MS1 and high res MS2 e.g. Q Exactive or Q-Tof
Database
CPU threads
Masses
- peptide_mass_tolerance_lower *
- peptide_mass_tolerance_upper *
- peptide_mass_units
- mass_type_parent
- mass_type_fragment
- precursor_tolerance_type
- isotope_error **
Search enzyme
Fragment ions
- fragment_bin_tol
- fragment_bin_offset
- theoretical_fragment_ions
- use_A_ions
- use_B_ions
- use_C_ions
- use_X_ions
- use_Y_ions
- use_Z_ions
- use_Z1_ions
- use_NL_ions
Output
- output_mzidentmlfile
- output_pepxmlfile
- output_percolatorfile
- output_sqtfile
- output_sqtstream
- output_txtfile
- output_outfiles
- print_expect_score
- num_output_lines
- show_fragment_ions
- sample_enzyme_number
mzXML/mzML parameters
Misc. parameters
- clip_nterm_aa
- clip_nterm_methionine
- decoy_prefix
- digest_mass_range
- equal_I_and_L
- mass_offsets
- max_duplicate_proteins
- max_fragment_charge
- max_index_runtime
- max_precursor_charge
- minimum_xcorr
- num_results
- nucleotide_reading_frame
- output_suffix
- peff_verbose_output
- peptide_length_range
- precursor_NL_ions
- skip_researching
- spectrum_batch_size
- text_file_extension
- explicit_deltacn
- old_mods_encoding
- export_additional_pepxml_scores *
- resolve_fullpaths *
- pinfile_protein_delimiter *
- set_X_residue aka set_A_residue through set_Z_residue *
Spectral processing
Variable modifications
- variable_mod01 thru variable_mod15 *,**
- max_variable_mods_in_peptide
- require_variable_mod
- scale_fragmentNL
Static modifications
- add_Cterm_peptide
- add_Nterm_peptide
- add_Cterm_protein
- add_Nterm_protein
- add_G_glycine
- add_A_alanine
- add_S_serine
- add_P_proline
- add_V_valine
- add_T_threonine
- add_C_cysteine
- add_L_leucine
- add_I_isoleucine
- add_N_asparagine
- add_D_aspartic_acid
- add_Q_glutamine
- add_K_lysine
- add_E_glutamic_acid
- add_M_methionine
- add_H_histidine
- add_F_phenylalanine
- add_U_selenocysteine
- add_R_arginine
- add_Y_tyrosine
- add_W_tryptophan
- add_O_pyrrolysine
- add_B_user_amino_acid
- add_J_user_amino_acid
- add_X_user_amino_acid
- add_Z_user_amino_acid