<HashMap><database>MetaboLights</database><file_versions><headers><Content-Type>application/xml</Content-Type></headers><body><files><Xlsx>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/FILES/metadata.xlsx</Xlsx><Tabular>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/m_MTBLS15115_LC-MS_negative_reverse-phase_v2_maf.tsv</Tabular><Txt>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/a_MTBLS15115_LC-MS_negative_reverse-phase.txt</Txt><Txt>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/i_Investigation.txt</Txt><Txt>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/s_MTBLS15115.txt</Txt><Wiff>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/FILES/RAW_FILES/AKG-20260622.wiff.scan</Wiff><Wiff>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/FILES/RAW_FILES/AKG-20260622.wiff</Wiff><Wiff>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/FILES/RAW_FILES/C13-AKG-NEG.wiff.scan</Wiff><Wiff>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115/FILES/RAW_FILES/C13-AKG-NEG.wiff</Wiff></files><type>primary</type></body><statusCodeValue>200</statusCodeValue><statusCode>OK</statusCode></file_versions><scores/><additional><ftp_download_link>ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15115</ftp_download_link><metabolite_identification_protocol>&lt;p>α-Ketoglutarate was identified by comparison with an authentic reference standard based on retention time and characteristic MRM transition (m/z 145.1 - 101.0). Quantification was further verified using the stable isotope-labeled internal standard (13C5-α-ketoglutaric acid). Calibration was performed using authentic α-ketoglutarate standards to ensure accurate metabolite identification and quantification.&lt;/p></metabolite_identification_protocol><repository>MetaboLights</repository><study_status>Public</study_status><ptm_modification></ptm_modification><instrument_platform>Liquid Chromatography MS - negative - reverse-phase</instrument_platform><chromatography_protocol>&lt;p>Chromatographic separation was performed using a liquid chromatography system coupled to a QTRAP 5500 mass spectrometer (AB Sciex, Framingham, MA, USA). Samples were separated on a T3 reversed-phase analytical column under optimized chromatographic conditions suitable for targeted α-KG quantification.&lt;/p></chromatography_protocol><publication>LC-MS/MS Quantification of Nuclear α-KG in NSCLC.</publication><submitter_name>Jiawen Cui</submitter_name><submitter_affiliation>China Phramaceutical University</submitter_affiliation><organism_part>endometabolome</organism_part><technology_type>mass spectrometry assay</technology_type><disease></disease><extraction_protocol>&lt;p>To quench metabolism and preserve intracellular α-ketoglutarate (α-KG), isolated nuclear pellets were extracted with 500 μL of pre-chilled 80% (v/v) methanol and incubated at −80°C for 2 h. Samples were centrifuged at 15,000 × g for 15 min at 4°C, and the supernatant containing extracted metabolites was collected and vacuum-dried. Prior to LC-MS/MS analysis, dried extracts were reconstituted in an appropriate solvent. Stable isotope-labeled 13C5-α-ketoglutaric acid was used as the internal standard.&lt;/p></extraction_protocol><organism>Homo sapiens</organism><full_dataset_link>https://www.ebi.ac.uk/metabolights/MTBLS15115</full_dataset_link><author>Jiawen Cui. China Phramaceutical University. cuijw0514@outlook.com.</author><author>Jiali Liu. China Pharmaceutical University. TongJiaXiang #24, Nanjing, Jiangsu, China. carrie_CPU@hotmail.com.</author><data_transformation_protocol>&lt;p>Raw LC-MS/MS data were processed using the manufacturer’s software to integrate chromatographic peak areas. Quantification was performed by comparing analyte-to-internal-standard peak area ratios with an external calibration curve generated using authentic α-ketoglutarate standards. Nuclear α-KG concentrations were subsequently calculated by normalizing the quantified α-KG amount to the estimated total nuclear volume, assuming an average nuclear volume of approximately 1 pL per cell.&lt;/p></data_transformation_protocol><study_factor>Treatment</study_factor><submitter_email>cuijw0514@outlook.com</submitter_email><sample_collection_protocol>&lt;p>Cultured cells were rapidly harvested on ice and washed with ice-cold phosphate-buffered saline (PBS). Nuclei were isolated immediately using a chilled sucrose-based fractionation protocol to minimize metabolic alterations. Cells were homogenized in ice-cold 0.25 M sucrose buffer (10 mM Tris-HCl, 3 mM MgCl2, pH 7.4), filtered, and layered onto a 0.34 M sucrose cushion. Following centrifugation at 700 × g for 10 min at 4°C, the nuclear pellet was collected and washed twice with 0.25 M sucrose buffer at 1,000 × g for 10 min. The purified nuclear pellet was immediately subjected to metabolite extraction.&lt;/p></sample_collection_protocol><omics_type>Metabolomics</omics_type><study_design>Metabolomics</study_design><study_design>Shimadzu SIL-20AC</study_design><study_design>QTRAP 5500</study_design><study_design>targeted analysis</study_design><study_design>cell culture</study_design><study_design>Homo sapiens</study_design><study_design>targeted metabolite profiling</study_design><study_design>non-small cell lung carcinoma</study_design><study_design>endometabolome</study_design><study_design>experimental sample</study_design><curator_keywords>Metabolomics</curator_keywords><curator_keywords>Shimadzu SIL-20AC</curator_keywords><curator_keywords>QTRAP 5500</curator_keywords><curator_keywords>targeted analysis</curator_keywords><curator_keywords>cell culture</curator_keywords><curator_keywords>Homo sapiens</curator_keywords><curator_keywords>targeted metabolite profiling</curator_keywords><curator_keywords>non-small cell lung carcinoma</curator_keywords><curator_keywords>endometabolome</curator_keywords><curator_keywords>experimental sample</curator_keywords><mass_spectrometry_protocol>&lt;p>Mass spectrometric analysis was performed on a QTRAP 5500 triple quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source operating in negative ion mode. Quantification was performed using multiple reaction monitoring (MRM). The MRM transition for α-ketoglutarate was m/z 145.1 - 101.0 with a declustering potential (DP) of −20 V and collision energy (CE) of −12 V. The isotopically labeled internal standard (13C5-α-ketoglutaric acid) was monitored using the transition m/z 151.06 - 105.0 with DP = −50 V and CE = −12 V. Instrument control and data acquisition were performed using the manufacturer’s software.&lt;/p></mass_spectrometry_protocol></additional><is_claimable>false</is_claimable><name>LC-MS/MS Quantification of Nuclear α-KG in NSCLC</name><description>This study contains targeted LC-MS/MS quantification of α-ketoglutarate (α-KG) in NSCLC cells using 13C-labeled α-KG internal standard. Nuclear α-KG levels were measured in A549, A549/DTX, PC9, and PC9/OR cells. In addition, nuclear α-KG was quantified in GLUD1-overexpressing A549 cells and GLUD1-knockdown A549/DTX cells. Mitochondrial α-KG measurements were performed exclusively in A549/DTX cells. The dataset includes raw SCIEX LC-MS/MS data, sample metadata, and processed quantitative results.</description><dates><publication>2026-07-21</publication><submission>2026-07-21</submission></dates><accession>MTBLS15115</accession><cross_references/></HashMap>