title: DirecTag: accurate sequence tags from peptide MS/MS through statistical scoring.
abstract: In shotgun proteomics, tandem mass spectra of peptides are typically identified through database search algorithms such as Sequest. We have developed DirecTag, an open-source algorithm to infer partial sequence tags directly from observed fragment ions. This algorithm is unique in its implementation of three separate scoring systems to evaluate each tag on the basis of peak intensity, m/ z fidelity, and complementarity. In data sets from several types of mass spectrometers, DirecTag reproducibly exceeded the accuracy and speed of InsPecT and GutenTag, two previously published algorithms for this purpose. The source code and binaries for DirecTag are available from http://fenchurch.mc.vanderbilt.edu.
authors.affiliation: Mass Spectrometry Research Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232-8575, USA. david.l.tabb@vanderbilt.edu
authors.forename: David L
authors.initials: DL
authors.lastname: Tabb
authors.forename: Ze-Qiang
authors.initials: ZQ
authors.lastname: Ma
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Martin
authors.forename: Amy-Joan L
authors.initials: AJ
authors.lastname: Ham
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Chambers
mesh_terms: D000465:Algorithms; D010455:Peptides / Q000737:chemistry*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010455:Peptides