{"database":"GNPS","file_versions":[{"headers":{"Content-Type":["application/json"]},"body":{"files":{"Other":["ftp://massive-ftp.ucsd.edu/v09/MSV000097637/"]},"type":"primary"},"statusCode":"OK","statusCodeValue":200}],"scores":null,"additional":{"omics_type":["Metabolomics"],"submitter":["Juergen Hartler","Edward A Dennis"],"instrument_platform":["ZenoTOF 7600","Q Exactive"],"species":["Homo Sapiens (ncbitaxon:9606)","Mus Musculus (ncbitaxon:10090)"],"full_dataset_link":["https://massive.ucsd.edu/ProteoSAFe/dataset.jsp?task=a69526cc26f04f098cb86d7804c686db"],"submitter_affiliation":["University of California, San Diego","University of Graz"],"submitter_email":["juergen.hartler@uni-graz.at","edennis@ucsd.edu"],"sample_protocol":[""],"repository":["GNPS"],"file_size":["3,055"],"ptm_modification":["MS:1002864 - No post-translational-modifications are included in the identified peptides of this dataset"],"data_protocol":[""],"additional_accession":[]},"is_claimable":false,"name":"GNPS - Computationally unmasking each fatty acyl C=C position in complex lipids by routine LC-MS/MS lipidomics","description":"Identifying carbon-carbon double bond (C=C) positions in complex lipids is essential for elucidating physiological and pathological processes. Currently, this is impossible in high-throughput analyses of native lipids without specialized instrumentation that compromises ion yields. Here, we demonstrate automated, chain-specific identification of C=C positions in complex lipids based on the retention time derived from routine reverse-phase chromatography tandem mass spectrometry (RPLC-MS/MS). We introduce LC=CL, a computational solution that utilizes a comprehensive database capturing the elution profile of more than 2,400 complex lipid species identified in RAW264.7 macrophages, including 1,145 newly reported compounds. Using machine learning, LC=CL provides precise and automated C=C position assignments, adaptable to any suitable chromatographic condition. To illustrate the power of LC=CL, we re-evaluated previously published data and discovered new C=C position-dependent specificity of cytosolic phospholipase A2 (cPLA2). Accordingly, C=C position information is now readily accessible for large-scale high-throughput studies with any MS/MS instrumentation and ion activation method.","dates":{"publication":"Tue Apr 15 22:04:00 BST 2025"},"accession":"MSV000097637","cross_references":{}}