MSnID

MSnID extracts and analyzes tandem mass spectrometry (MS/MS) identification data from mzIdentML files and plain-text search-result files to evaluate identification quality and optimize filtering under user-specified false discovery rate constraints.

Key Features:

• mzIdentML support: Parses mzIdentML files via the mzID package.
• Plain-text search-result support: Reads and processes plain-text search-result files from proteomics experiments.
• Data integration: Integrates search results across multiple datasets for comprehensive analysis.
• Filtering optimization and FDR control: Optimizes filtering criteria to maximize identification numbers while enforcing a user-specified false discovery rate (FDR).
• Enzymatic cleavage analysis: Evaluates missed and irregular enzymatic cleavages.
• Mass measurement accuracy assessment: Assesses mass measurement accuracy for peptide identifications.

Scientific Applications:

• Proteomics research: Supports accurate identification and quantification of proteins from complex biological samples and high-throughput proteomic studies.
• Enzymatic digestion optimization: Informs refinement of enzymatic digestion protocols by analyzing cleavage patterns and missed cleavages.
• MS/MS data validation: Validates peptide identifications through assessment of mass measurement accuracy.

Methodology:

Parses mzIdentML via the mzID package within the R/Bioconductor ecosystem and processes plain-text search results; performs filtering optimization to maximize identifications subject to a user-specified FDR and computes enzymatic cleavage statistics and mass measurement accuracy.