Peptide-Spectrum Match Validation with Internal Standards (P-VIS): Internally-Controlled Validation of Mass...

Area of Science:

• Biochemistry
• Proteomics
• Analytical Chemistry

Background:

• Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is crucial for disease-related protein studies.
• Advancements in instrumentation and data analysis allow deeper proteome and peptidome profiling.
• A standardized method is needed to validate peptide-spectrum matches (PSMs).

Purpose of the Study:

• To develop and present a novel, broadly applicable workflow for validating PSMs.
• To introduce PSM validation with internal standards (P-VIS) as a rigorous approach.
• To enhance the reliability of peptide identification in mass spectrometry.

Main Methods:

• The P-VIS workflow compares fragmentation spectra and chromatographic retention times of biological peptides with synthetic standards.
• Similarity measurements from internal standards are used to establish prediction intervals for valid matches.
• A peptide match is deemed valid if its similarity falls within the calculated prediction interval.

Main Results:

• P-VIS provides a systematic and objective method for assessing individual PSM validity.
• The workflow establishes a measurable degree of confidence for peptide identifications.
• Internal standards enable precise validation of peptide-spectrum matches.

Conclusions:

• P-VIS offers a robust solution for the critical need for standardized PSM validation.
• This workflow enhances the reliability and interpretability of LC-MS/MS-based proteomic and peptidomic data.
• P-VIS facilitates more confident peptide identification in disease research and other applications.