title: Development and validation of a spectral library searching method for peptide identification from MS/MS.
abstract: A notable inefficiency of shotgun proteomics experiments is the repeated rediscovery of the same identifiable peptides by sequence database searching methods, which often are time-consuming and error-prone. A more precise and efficient method, in which previously observed and identified peptide MS/MS spectra are catalogued and condensed into searchable spectral libraries to allow new identifications by spectral matching, is seen as a promising alternative. To that end, an open-source, functionally complete, high-throughput and readily extensible MS/MS spectral searching tool, SpectraST, was developed. A high-quality spectral library was constructed by combining the high-confidence identifications of millions of spectra taken from various data repositories and searched using four sequence search engines. The resulting library consists of over 30,000 spectra for Saccharomyces cerevisiae. Using this library, SpectraST vastly outperforms the sequence search engine SEQUEST in terms of speed and the ability to discriminate good and bad hits. A unique advantage of SpectraST is its full integration into the popular Trans Proteomic Pipeline suite of software, which facilitates user adoption and provides important functionalities such as peptide and protein probability assignment, quantification, and data visualization. This method of spectral library searching is especially suited for targeted proteomics applications, offering superior performance to traditional sequence searching.
authors.affiliation: Institute for Systems Biology, Seattle, WA, USA.
authors.forename: Henry
authors.initials: H
authors.lastname: Lam
authors.forename: Eric W
authors.initials: EW
authors.lastname: Deutsch
authors.forename: James S
authors.initials: JS
authors.lastname: Eddes
authors.forename: Jimmy K
authors.initials: JK
authors.lastname: Eng
authors.forename: Nichole
authors.initials: N
authors.lastname: King
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Stein
authors.forename: Ruedi
authors.initials: R
authors.lastname: Aebersold
mesh_terms: D030562:Databases, Protein; D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D040901:Proteomics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry; D012984:Software; D053719:Tandem Mass Spectrometry
chemical_list: D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins