We present a tool to improve quantitative accuracy and precision in mass spectrometry based on shotgun proteomics: protein quantification by peptide quality control, PQPQ. The method is based on the assumption that the quantitative pattern of peptides derived from one protein will correlate over several samples. Dissonant patterns arise either from outlier peptides or because of the presence of different protein species. By correlation analysis, protein quantification by peptide quality control identifies and excludes outliers and detects the existence of different protein species. Alternative protein species are then quantified separately. By validating the algorithm on seven data sets related to different cancer studies we show that data processing by protein quantification by peptide quality control improves the information output from shotgun proteomics. Data from two labeling procedures and three different instrumental platforms was included in the evaluation. With this unique method using both peptide sequence data and quantitative data we can improve the quantitative accuracy and precision on the protein level and detect different protein species.
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http://dx.doi.org/10.1074/mcp.M111.010264 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Bioengineering, California Institute of Technology, Pasadena, CA 91125.
The diversity and heterogeneity of biomarkers has made the development of general methods for single-step quantification of analytes difficult. For individual biomarkers, electrochemical methods that detect a conformational change in an affinity binder upon analyte binding have shown promise. However, because the conformational change must operate within a nanometer-scale working distance, an entirely new sensor, with a unique conformational change, must be developed for each analyte.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.
X-ray spectroscopies are uniquely poised to describe the geometric and electronic structure of metalloenzyme active sites under a wide variety of sample conditions. UV/Vis (ultraviolet/visible) spectroscopy is a similarly well-established technique that can identify and quantify catalytic intermediates. The work described here reports the first simultaneous collection of full in situ UV/Vis and high-energy resolution fluorescence detected x-ray absorption spectra.
View Article and Find Full Text PDFJ Extracell Biol
January 2025
RoseBio Milano Italy.
Current state-of-the-art tools for analysing extracellular vesicles (EVs) offer either highly sensitive but unidimensional bulk measurements of EV components, or high-resolution multiparametric single-particle analyses which lack standardization and appropriate reference materials. This limits the accuracy of the assessment of marker abundance and overall marker distribution amongst individual EVs, and finally, the understanding of true EV heterogeneity. In this study, we aimed to define the standardized operating procedures and reference material for fluorescent characterization of EVs with two commonly used EV analytical platforms-nanoparticle tracking analysis (NTA) and nano-flow cytometry (nFCM).
View Article and Find Full Text PDFBMC Med Inform Decis Mak
January 2025
Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Stadium Road, Karachi, 74800, Pakistan.
Background: Reference intervals (RIs) are crucial for distinguishing healthy from sick individuals and vary across age groups. Hemoglobinopathies are common in Pakistan, making the quantification of hemoglobin variants essential for screening. Direct RIs are established by measuring values from a healthy reference population, whereas indirect RIs, use statistical analysis of routine lab data to estimate values, making it feasible in settings where direct data is unavailable.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Hepatobiliary and Pancreatic Surgery, Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Shiyan, 442000, Hubei, China.
Pembrolizumab plus Lenvatinib is regarded as a significant treatment option for advanced unresectable hepatocellular carcinoma (HCC). This study aims to meticulously monitor and identify adverse events (AEs) related to this combined therapy, enhance patient safety, and offer evidence-based recommendations for the appropriate use of these drugs. We gathered adverse drug reactions (ADRs)-related data from the FAERS database for HCC patients who received Pembrolizumab, both alone and in combination with Lenvatinib from the first quarter of 2014 to the fourth quarter of 2023.
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