Fast and accurate database searches with MS-GF+Percolator

J Proteome Res. 2014 Feb 7;13(2):890-7. doi: 10.1021/pr400937n. Epub 2013 Dec 23.


One can interpret fragmentation spectra stemming from peptides in mass-spectrometry-based proteomics experiments using so-called database search engines. Frequently, one also runs post-processors such as Percolator to assess the confidence, infer unique peptides, and increase the number of identifications. A recent search engine, MS-GF+, has shown promising results, due to a new and efficient scoring algorithm. However, MS-GF+ provides few statistical estimates about the peptide-spectrum matches, hence limiting the biological interpretation. Here, we enabled Percolator processing for MS-GF+ output and observed an increased number of identified peptides for a wide variety of data sets. In addition, Percolator directly reports p values and false discovery rate estimates, such as q values and posterior error probabilities, for peptide-spectrum matches, peptides, and proteins, functions that are useful for the whole proteomics community.

MeSH terms

  • Algorithms
  • Databases, Protein*
  • Information Storage and Retrieval*
  • Mass Spectrometry / methods*