Libra

Libra analyzes 4- and 8-channel iTRAQ (Isobaric Tags for Relative and Absolute Quantitation) MS/MS data for quantitative mass spectrometry-based proteomics within the Trans-Proteomic Pipeline (TPP).

Key Features:

• 4- and 8-channel iTRAQ support: Supports quantification of 4- and 8-channel iTRAQ labeling schemes for comparative proteomics.
• Integrated workflow: Processes raw spectrometer output through an integrated pipeline that includes file conversion and downstream protein-level analysis.
• Quantification by stable isotope ratios: Performs quantification based on stable isotope ratios derived from iTRAQ reporter ions.
• Protein-level statistical validation: Provides statistical validation of quantitation results at the protein level.
• Integration with TPP: Implemented as a component of the Trans-Proteomic Pipeline (TPP).

Scientific Applications:

• Disease mechanism studies: Quantitative comparison of protein abundance across conditions to investigate disease-related proteomic changes using iTRAQ-labeled MS/MS data.
• Biomarker discovery: Identification and relative quantification of candidate protein biomarkers across samples with iTRAQ-based quantitation.
• Cellular response analysis: Measurement of changes in protein expression in response to stimuli or treatments using iTRAQ MS/MS quantitation.

Methodology:

Converts spectrometer output files, performs quantification based on stable isotope ratios for iTRAQ-labeled samples, and carries out protein-level statistical validation within the Trans-Proteomic Pipeline.