Comparison of DIA to spectral counting and TMT quantitative techniques using animal lens studies - pwilmart/quantitative_proteomics_comparison

Single-cell mass spectrometry-based proteomics (SCP) can resolve cellular heterogeneity in complex biological systems and provide a system-level view of the proteome of each cell. Major advancements i...

A Structures for Lossless Ion Manipulation-Orbitrap Exploris 480 (SLIM-OE) ion mobility mass spectrometry (IM-MS) platform was developed, integrating SLIM IM separation with Orbitrap MS analysis. A “s...

Mass spectrometry based targeted proteomics methods provide a sensitive and high-throughput analysis of selected proteins. To develop a targeted bottom-up proteomics assay, peptides must be evaluated as proxies for the measurement of a protein or proteoform in a biological matrix. Candidate peptide selection typically relies on predetermined biochemical properties, data from semistochastic sampling, or empirical measurements. These strategies require extensive testing and method refinement due to the difficulties associated with prediction of the peptide response in the biological matrix of interest. Gas-phase fractionated (GPF) narrow window data-independent acquisition (DIA) aids in the development of reproducible selected reaction monitoring (SRM) assays by providing matrix-specific information on peptide detectability and quantification by mass spectrometry. To demonstrate the suitability of DIA data for selecting peptide targets, we reimplement a portion of an existing assay to measure 98 Alzheimer’s disease proteins in cerebrospinal fluid (CSF). Peptides were selected from GPF-DIA based on signal intensity and reproducibility. The resulting SRM assay exhibits a quantitative precision similar to that of published data, despite the inclusion of different peptides between the assays. This workflow enables development of new assays without additional upfront data acquisition, demonstrated here through generation of a separate assay for an unrelated set of proteins in CSF from the same data set.

Systematic mapping of protein-ligand interactions is essential for understanding biological processes and drug mechanisms. Peptide-centric local stability assay (PELSA) is a powerful tool for detectin...

Despite advances in clinical proteomics, translating protein biomarker discoveries into clinical use remains challenging due to the technical complexity of the validation process. Targeted MS-based proteomics approaches such as parallel reaction monitoring (PRM) offer sensitive and specific assays for biomarker translation. In this study, we developed a multiplex PRM assay using the Stellar mass spectrometry platform to quantify 57 plasma proteins, including 21 FDA-approved proteins. Loading curves (11-points) were performed at 4 sample throughputs (100, 144, 180, and 300 samples per day) using independent, optimized, and scheduled PRM methods. Following optimization, an inflammatory bowel disease (IBD) cohort of plasma samples (493 IBD, 509 matched controls) was analyzed at a throughput of 180 SPD. To monitor system performance, the study also included 1,000 additional injections for system suitability tests, low-, middle-, and high-quality controls, washes, and blanks. Using this approach, we observed high quantifiability (linearity, sensitivity, reproducibility) in the PRM assay and consistent in data acquisition across a large cohort. We also validated the candidate IBD markers, C-reactive protein and orosomucoid protein, identified in a recent discovery experiment.

Multistep multihour tryptic proteolysis has limited the utility of bottom-up proteomics for cases that require immediate quantitative information. The power of proteomics to quantify biomarkers of health status cannot practically assist in clinical care if the dynamics of disease outpaces the turnaround of analysis. The recently available hyperthermoacidic archaeal (HTA) protease “Krakatoa” digests samples in a single 5 to 30 min step at pH 3 and >80 °C in conditions that disrupt most cells and tissues, denature proteins, and block disulfide reformation thereby dramatically expediting and simplifying sample preparation. The combination of quick single-step proteolysis with high-throughput dual-trapping single analytical column (DTSC) liquid chromatography–mass spectrometry (LC–MS) returns actionable data in less than 1 h from collection of unprocessed biofluid. The systematic evaluation of this methodology finds that over 160 proteins are quantified in less than 1 h from 1 μL of whole blood. Furthermore, labile Angiotensin I and II bioactive peptides along with a panel of protein species can be measured at 8 min intervals with a 20 min initial lag using targeted MS. With these methods, we analyzed serum and plasma from 53 individuals and quantified Angiotensin I and II and over 150 proteins including at least 46 that were not detected with trypsin. We discuss some of the implications of real-time proteomics including the immediate potential to advance several clinical and research applications.

molecular genetics, classification of proteins, methodology in biological sciences, cancer, and cell biology

Gaia is an embedding-based search engine for sequences.

The John Innes Centre (JIC) seeks a talented, motivated individual as a proteomics specialist to serve the growing needs of proteomics-based technology at JIC, which is a globally recognized…

In eukaryotic organisms, protein kinases regulate diverse protein activities and signaling pathways through phosphorylation of specific protein substrates. Isolating and characterizing kinase substrat...

A web-based platform for the analysis of untargeted metabolomics with multi-omics integrative approach

PTMVision: Interactive Visualization of Post Translational Modifications | Understanding the intricate landscape of post-translational modifications (PTMs) is crucial for unraveling the co...

The National Cancer Institute’s Clinical Proteomics Tumor Analysis Consortium (CPTAC) was established to address the need for improved design, standardization, and validation of proteomics assays to enable better translation of biomarkers from the analytical lab to the clinic. Here, we applied CPTAC guidelines to characterize quantitative mass spectrometry (MS) assays in a new multiple reaction monitoring (MRM) proteomics panel. The panel of 50 proteins was developed in response to a previous study that identified a proteomic profile of altered translational control associated with response to a new cancer drug. MRM-MS assays for 53 peptides of interest were developed, optimized, and characterized on a UPLC system coupled to a triple-quadrupole mass spectrometer (QQQ-MS) using synthetic proteotypic peptides and corresponding stable-isotope labeled internal standard (SIS) peptides. Most of the assays were found to be fit-for-purpose for biomarker verification in that they precisely and reproducibly quantify the peptides at levels corresponding to the endogenous concentration in the desired cancer cell lines. Of these, 28 peptide assays represent to proteins that previously had no associated assays published in the CPTAC database. The targeted proteins in this publicly deposited validated multiplexed panel may be of use for research applications in cancer, cellular stress, neurology, cardiology, and metabolism.

Cell Research - Comprehensive discovery and functional characterization of the noncanonical proteome