Principles of PRM Quantitative Proteomics
Parallel Reaction Monitoring (PRM) is a targeted quantitative proteomic approach that employs high-resolution mass spectrometry. It has become an essential tool for advanced quantitative analysis in life sciences. Compared with the conventional Selected Reaction Monitoring (SRM) technique, PRM utilizes Orbitrap or Time-of-Flight (TOF) mass spectrometers to perform comprehensive monitoring of fragment ions, thereby achieving superior selectivity, sensitivity, and reproducibility.
Working Principles of PRM Quantitative Proteomics
1. Selection of Targeted Peptides
The first step of PRM analysis involves selecting signature peptides of target proteins based on prior Data-Dependent Acquisition (DDA) results, literature reports, or database information. These peptides serve as the fundamental units for quantitative measurement.
2. Precursor Ion Selection
Through the standard quadrupole ion selection system, PRM isolates the precursor ions that are transmitted into the high-resolution analyzer for subsequent fragmentation.
3. High-Energy Collisional Dissociation (HCD)
After precursor ion selection, the ions undergo HCD to generate a set of characteristic fragment ions, which are used as quantitative indicators.
4. Comprehensive Product Ion Analysis
PRM simultaneously analyzes all fragment ions in a single full-scan acquisition. Using high-resolution, high-accuracy Orbitrap or TOF mass spectrometry, PRM provides precise and reliable quantification based on multiple ion correlations.
Technical Advantages of PRM Quantitative Proteomics over SRM
1. High Resolution and Comprehensive Detection Enable Superior Selectivity
(1) Unlike SRM, which requires predefinition of specific ion pairs, PRM conducts full-spectrum acquisition of all product ions with high-resolution detection, substantially minimizing potential interferences among peptides. This eliminates the need to individually optimize transitions for each peptide, simplifying method development.
(2) PRM requires only the selection of precursor peptides, while the downstream ion analysis is automated, resulting in lower maintenance demands and reduced method complexity compared to SRM.
2. Achieving Absolute Quantification through Stable Isotope Labeling
PRM can be integrated with Stable Isotope-labeled Standard peptides to enable absolute quantification. This capability is particularly valuable in biomarker validation and metabolic flux studies.
3. High-Information-Content Full-Spectrum Data
The comprehensive full-scan data generated by PRM enable advanced functionalities such as retrospective data reanalysis, repeated verification, and multidimensional data inspection.
Application Scenarios of PRM Quantitative Proteomics
1. Biomarker Validation
PRM enables precise quantification of candidate disease biomarkers identified during the discovery phase. It facilitates evaluation of their stability, reproducibility, and specificity across large cohorts of clinical samples.
2. Quantitative Analysis of Signaling Pathway Proteins
PRM is particularly well-suited for validating key proteins involved in specific signaling pathways, supporting studies of molecular mechanisms and pharmacodynamic pathways.
3. Quality Control of Biopharmaceuticals
In biotherapeutic characterization and potency assessment, PRM provides highly accurate quantification of specific expression levels and post-translational modification sites, even at very low abundance.
4. Greater Flexibility Compared with DIA
Unlike Data-Independent Acquisition (DIA), which relies on pre-established spectral libraries, PRM offers greater flexibility. New peptides can be readily added based on emerging discoveries, and scanning ranges or acquisition parameters can be easily adjusted for future analyses.
MtoZ Biolabs is equipped with a high-performance Orbitrap Exploris 480 system and a proprietary peptide library, providing a fully integrated PRM-based quantitative proteomics service, from experimental design, peptide selection, and isotope labeling configuration to data interpretation. Our standardized workflow has been successfully applied to over a hundred collaborative projects, including tumor quantification, immune regulation, biomarker verification, and pharmacokinetic analysis, delivering high selectivity and reproducible data quality. For customized PRM quantitative solutions tailored to your research or to discuss potential collaborations, please visit our official website or contact our technical support team. We are committed to providing expert guidance and personalized analytical solutions.
MtoZ Biolabs, an integrated chromatography and mass spectrometry (MS) services provider.
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