Peptidequant

Peptidequant estimates peptide abundances from mass spectrometry data using an optimization-based approach that leverages isotopic distributions and elution profile smoothness to resolve co‑eluting peptides and control peak intensity variation.

Key Features:

• Optimization-Based Approach: Employs an optimization-based method that integrates isotopic distributions and elution profile smoothness to estimate peptide abundances.
• Handling Peptide Overlapping: Differentiates co‑eluting and overlapping peptides by modeling isotopic distribution patterns from mass spectrometry data.
• Controlling Peak Intensity Variation: Incorporates strategies to control variability in peak intensity to improve consistency of quantification across samples.
• Variance and Bias Trade-off Consideration: Exposes a variance-related parameter to balance estimation variance and bias for optimal performance.
• Comparative Performance: Validated against commonly used methods on simulated datasets and two real datasets comprising standard protein mixtures.
• Parameter Selection Guidance: Provides guidance for selecting parameters based on analysis of the variance–bias trade-off.

Scientific Applications:

• Protein expression profiling: Enables more accurate peptide-level quantification for protein expression profiling from mass spectrometry data.
• Biomarker discovery: Supports biomarker discovery by reducing quantification variance and bias in peptide measurements.
• Pathway analysis and interpretation: Improves reliability of peptide abundance estimates used in biological pathway analyses.

Methodology:

Uses an optimization-based estimation that leverages isotopic distributions and enforces elution profile smoothness, models isotopic distribution patterns to resolve overlapping peptides, incorporates a variance-related parameter to balance variance and bias, and was validated via comparisons on simulated datasets and two real datasets comprising standard protein mixtures.