Biology subjects

Chen, Z. A.

Publications and source records attributed to Chen, Z. A..

4 recordsLinked to original sources

bioRxiv2025

MetaXtract: Extracting Metadata from Raw Files for FAIR Data Practices and Workflow Optimisation

Mass spectrometry (MS) experiments generate rich acquisition metadata that are essential for reproducibility, data sharing, and quality control (QC). Because these metadata are typically stored only in vendor-specific formats, they often remain difficult to access. MetaXtract is a lightweight tool that extracts detailed parameters directly from Thermo Fisher raw files and exposes them in structured, tabular formats. By capturing sample information, LC-MS method settings, and scan-level metrics such as retention time, total ion current, and ion injection time, MetaXtract increases transparency and ensures that essential acquisition details accompany published data and results in easy readable form. This supports FAIR data practices by improving the findability, accessibility, interoperability, and reusability of MS datasets after converting them to other formats, thereby increasing the value of deposition in public repositories. The importance of such metadata accessibility was recently highlighted by the crosslinking mass spectrometry community in efforts to advance FAIR data principles, and it extends to MS-based omics approaches more broadly. Importantly, MetaXtract enables search-free, near real-time performance monitoring by relying on acquisition-side signals, providing actionable indicators immediately after data acquisition rather than after database searching. This also caters for laboratory or depository internal streamlined QC and troubleshooting through integration into automated pipelines. By embedding acquisition parameters into routine data handling, MetaXtract strengthens reproducibility, optimises method development, and supports large-scale applications, including machine learning and secondary data analysis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=195 HEIGHT=200 SRC="FIGDIR/small/687968v2_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@d835e6org.highwire.dtl.DTLVardef@babfaforg.highwire.dtl.DTLVardef@7e9d69org.highwire.dtl.DTLVardef@907993_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIMetadata extraction from Thermo Fisher raw files C_LIO_LIEnhanced findability, accessibility, interoperability, and reusability of deposited data C_LIO_LIIntegration into workflows via GUI and command-line modes C_LIO_LITroubleshooting support by visualizing MS1/MS2 scan details C_LIO_LIIndexed MS1/MS2 peak list export enabling machine learning workflows C_LI AvailabilityMetaXtract is available for free download as open-source software at https://github.com/Rappsilber-Laboratory/MetaXtract, the software is licensed under the Apache-2.0 license.

bioinformatics↗

bioRxiv2024

Molecular insights into dynamic protein structures by high-contrast crosslinking mass spectrometry

Proteins are comprised of structured domains and dynamic regions, and both are essential for biological function. However, studying dynamic regions is challenging using most structural biology methods, including crosslinking mass spectrometry. Here, we dramatically improve the usefulness of distance restraints from crosslinking MS by taking advantage of short-lived reactive species generated from diazirine-based photo-crosslinking. This leads to a clear view of complex topologies and conformational changes, including in dynamic regions. We demonstrate that photo-crosslinking MS data can be used to model flexible regions and conformational changes in the DNA repair complexes; Fanconi Anemia core complex and FANCD2-FANCI. In addition, we obtain new insights into the architecture and arrangement of the highly flexible CCR4-NOT mRNA deadenylation complex. The improved contrast of photo-crosslinking empowers structural biology by providing clearer structural insights into dynamic biological systems that have eluded other structural biology approaches.

molecular biology↗

bioRxiv2020

A Structure-Based Mechanism for DNA Entry into the Cohesin Ring

Despite key roles in sister chromatid cohesion and chromosome organization, the mechanism by which cohesin rings are loaded onto DNA is still unknown. Here, we combine biophysical approaches and cryo-EM to visualize a cohesin loading intermediate in which DNA is locked between two gates that lead into the cohesin ring. Building on this structural framework, we design biochemical experiments to establish the order of events during cohesin loading. In an initial step, DNA traverses an N-terminal kleisin gate that is first opened upon ATP binding and then closed as the cohesin loader locks the DNA against a shut ATPase gate. ATP hydrolysis leads to ATPase gate opening to complete DNA entry. Whether DNA loading is successful, or rather results in loop extrusion, might be dictated by a conserved kleisin N-terminal tail that guides the DNA through the kleisin gate. Our results establish the molecular basis for cohesin loading onto DNA.

molecular biology↗

bioRxiv2018

An integrated workflow for cross-linking/mass spectrometry

We present a concise workflow to enhance the mass spectrometric detection of cross-linked peptides by introducing sequential digestion and the cross-link identification software Xi. Sequential digestion enhances peptide detection by shortening long tryptic peptides while avoiding over-digestion. We demonstrate our simple 12-fraction protocol for cross-linked multi-protein complexes and cell lysates, quantitative analysis, and high-density cross-linking, without requiring specific cross-linker features. This overall approach reveals dynamic protein-protein interaction sites, which are accessible, have fundamental functional relevance and are therefore ideally suited for the development of small molecule inhibitors.

biochemistry↗