Technical Overview, peptide table

Revision as of 18:59, 16 February 2009

The peptide table records the details for each peptide identification, which is in turn used to identify the proteins in a GPM result file. If a GPM result file had no successful protein identifications, there will be no entries in the peptide table associated with it through the protein table.

The contents of this table are updated incrementally as part of the update procedure which executes daily.

Columns:

• pepid: the unique identifier for a specific peptide record.
• proid: the unique identifier for the protein with which this peptide identification is associated.
• seq: the residue sequence of the peptide.
• mh: the mass (in Daltons) of the peptide, as measured by the instrument which generated the original data file.
• expect: the base-10 logarithm of the chance that the identification of this peptide was an accidental random match. E.g., if the expect value is -4.0, the odds of this peptide identification being a random match are 1 in 10,000.
• start: the start location of this peptide's residue sequence in its associated protein residue sequence.
• end: the end location of this peptide's residue sequence in its associated protein residue sequence.
• charge: the charge of the ion as measured by the insturment which generated the original data file.
• delta: the difference between the mass as measured by the instrument and the theoretically calculated mass given the peptide's residue sequence.
• dida: the 1-based sequence of this mass spectrum in the original data file.
• didb: the identifier for this particular mass spectrum.
• didc: the 1-based sequence of specific measurement of this mass spectrum.