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Biology subjects

MacLean, B.

Publications and source records attributed to MacLean, B..

4 recordsLinked to original sources

Koina: Democratizing machine learning for proteomics research

Recent developments in machine-learning (ML) and deep-learning (DL) have immense potential for applications in proteomics, such as generating spectral libraries, improving peptide identification, and optimizing targeted acquisition modes. Although new ML/DL models for various applications and peptide properties are frequently published, the rate at which these models are adopted by the community is slow, which is mostly due to technical challenges. We believe that, for the community to make better use of state-of-the-art models, more attention should be spent on making models easy to use and accessible by the community. To facilitate this, we developed Koina, an open-source containerized, decentralized and online-accessible high-performance prediction service that enables ML/DL model usage in any pipeline. Using the widely used FragPipe computational platform as example, we show how Koina can be easily integrated with existing proteomics software tools and how these integrations improve data analysis.

bioinformatics↗

A Workflow for Improved Analysis of Cross-linking Mass Spectrometry Data Integrating Parallel Accumulation-Serial Fragmentation with MeroX and Skyline

Cross-linking mass spectrometry (XL-MS) has evolved into a pivotal technique for probing protein interactions. This study describes the implementation of Parallel Accumulation-Serial Fragmentation (PASEF) on timsTOF instruments, enhancing the detection and analysis of protein interactions by XL-MS. Addressing the challenges in XL-MS, such as the interpretation of complex spectra, low abundant cross-linked peptides, and a data acquisition bias, our current study integrates a peptide-centric approach for the analysis of XL-MS data and presents the foundation for integrating data-independent acquisition (DIA) in XL-MS with a vendor-neutral and open-source platform. A novel workflow is described for processing data-dependent analysis (DDA) of PASEF-derived information. For this, software by Bruker Daltonics is used, enabling the conversion of these data into a format that is compatible with MeroX and Skyline software tools. Our approach significantly improves the identification of cross-linked products from complex mixtures, allowing the XL-MS community to overcome current analytical limitations.

bioinformatics↗

Localization and Quantification of Post-Translational Modifications of Proteins Using Electron Activated Dissociation Fragmentation on a Fast-Acquisition Time-of-Flight Mass Spectrometer

Protein post-translational modifications (PTMs) are crucial and dynamic players in a large variety of cellular processes and signaling, and proteomic technologies have emerged as the method of choice to profile PTMs. However, these analyses remain challenging due to potential low PTM stoichiometry, the presence of multiple PTMs per proteolytic peptide, PTM site localization of isobaric peptides, and labile PTM groups that lead to neutral losses. Collision-induced dissociation (CID) is commonly used for to characterize PTMs, but the application of collision energy can lead to neutral losses and incomplete peptide sequencing for labile PTM groups. In this study, we compared CID to an alternative fragmentation, electron activated dissociation (EAD), operated on a recently introduced fast-acquisition quadrupole-time-of-flight (QqTOF) mass spectrometer. We analyzed a series of synthetic modified peptides, featuring phosphorylated, succinylated, malonylated, and acetylated peptides. We performed targeted, quantitative parallel reaction monitoring (PRM or MRMHR) assays to assess the performances of EAD to characterize, site-localize and quantify peptides with labile modifications. The tunable EAD kinetic energy allowed the preservation of labile modifications and provided better peptide sequence coverage with strong PTM-site localization fragment ions. Zeno trap activation provided significant MS/MS sensitivity gains by an average of 6-11-fold for EAD analyses, regardless of modification type. Evaluation of the quantitative EAD PRM workflows revealed high reproducibility with coefficients of variation of typically [~]2%, as well as very good linearity and quantification accuracy. This novel workflow, combining EAD and Zeno trap, offers confident, accurate, and robust characterization and quantification of PTMs.

biochemistry↗

Avant-garde: An automated data-driven DIA data curation tool.

Data-Independent Acquisition (DIA) is a technique that promises to comprehensively detect and quantify all peptides above an instruments limit of detection. Several software tools to analyze DIA data have been developed in recent years. However, several challenges still remain, like confidently identifying peptides, defining integration boundaries, dealing with interference for selected transitions, and scoring and filtering of peptide signals in order to control false discovery rates. In practice, a visual inspection of the signals is still required, which is impractical with large datasets. Avant-garde is a new tool to refine DIA (and PRM) by removing interfered transitions, adjusting integration boundaries and scoring peaks to control the FDR. Unlike other tools where MS runs are scored independently from each other, Avant-garde uses a novel data-driven scoring strategy. DIA signals are refined by learning from the data itself, using all measurements in all samples together to achieve the best optimization. We evaluated the performances of Avant-garde with a calibrated sample using spiked-in standards in a complex background, a phospho-enriched dataset (Abelin et al, 2016), and two complex hybrid proteome samples for benchmarking DIA software tools. The results clearly showed that Avant-garde is capable of improving the selectivity, accuracy, and reproducibility of the quantification results in very complex biological matrices. We have further shown that it can evaluate the suitability of a peak to be used for quantification reaching the same levels of selectivity, accuracy, and reproducibility obtained with manual validation.

bioinformatics↗