Abstract #100
Section: Ruminant Nutrition
Session: Ruminant Nutrition Symposium: Metabolomics Applications in Dairy Cow Metabolism
Format: Oral
Day/Time: Monday 9:30 AM–10:00 AM
Location: 319/320
Presentation is being recorded
Session: Ruminant Nutrition Symposium: Metabolomics Applications in Dairy Cow Metabolism
Format: Oral
Day/Time: Monday 9:30 AM–10:00 AM
Location: 319/320
Presentation is being recorded
# 100
Discovering isomeric milk metabolites with liquid chromatography drift tube-ion mobility mass spectrometry.
T. Shen1, I. Blaženovic1, O. Fiehn*1, 1West Coast Metabolomics Center, University of California-Davis, Davis, CA.
Key Words: metabolomics, lipidomics, mass spectrometry
Speaker Bio
Discovering isomeric milk metabolites with liquid chromatography drift tube-ion mobility mass spectrometry.
T. Shen1, I. Blaženovic1, O. Fiehn*1, 1West Coast Metabolomics Center, University of California-Davis, Davis, CA.
An overview is given on mass spectrometry-based metabolomics: past, current, and future developments. Understanding the metabolome is challenging due to the enormous diversity of metabolite structures. Metabolomics uses a range of tools, established as service at the NIH West Coast Metabolomics Center at UC Davis. We here explore the use of ion mobility spectrometry (IMS) in combination with liquid chromatography (LC) and high resolution mass spectrometry (MS) for milk analysis by increasing total peak capacity, specifically to distinguish isobaric and isomeric species that are not resolved by LC-MS alone. As example, we used LC-IM-QTOF MS for unraveling the complex lipidome compositions in human, goat and cow milk. Measurements were performed on an Agilent 1290 Infinity II LC with 6560 drift tube-ion mobility-QTOF MS system using a Waters Acquity CSH C18 column with a 15 min-gradient of isopropanol/acetonitrile (90:10, B) varied from 15% to 99% and acetonitrile:water (60:40, A), ammonium formate/formic acid buffered. Twenty µL of milk samples were extracted with MTBE and methanol. Dried extracts were reconstituted in methanol before LC-IM-MS analysis. Measured ion mobility drift times were corrected with external calibration for time spent outside the drift tube for precise determination of collision cross sections. We optimized the control over ion trapping in the drift cell. We analyzed lipid extract from 3 types of milk samples with untargeted LC-IM-MS. IM mode provided 6x more molecular features compared with regular LC-MS analysis without ion mobility. Using Agilent Mass Profiler to report IM peak feature, we developed a specific command line tool in R to characterize co-eluting isobaric species, followed by downstream identification by MS-DIAL. Our R command screened the IM features that exhibited distinct IM drift time (e.g., ?DT > 0.4 msec) by approximate m/z and LC retention time. We reduced the false discovery rate by evaluating DT intensities and m/z-specific DT after fitting a power-law regression. We discovered 73 isobaric species in milk lipidomic extracts that required ion mobility separation in addition to LC-QTOF MS.
Key Words: metabolomics, lipidomics, mass spectrometry
Speaker Bio
Prof. Oliver Fiehn has pioneered developments and applications in metabolomics with over 220 publications to date, starting in 1998 as postdoctoral scholar and from 2000 onwards as group leader at the Max-Planck Institute for Molecular Plant Physiology in Potsdam, Germany. Since 2004 he is Professor at the UC Davis Genome Center, overseeing his research laboratory and the satellite core service laboratory in metabolomics research. Since 2012, he serves as Director of the NIH West Coast Metabolomics Center, supervising 35 staff operating 16 mass spectrometers and coordinating activities with three UC Davis satellite labs, including efforts for combined interpretation of genomics and metabolomics data. The West Coast Metabolomics Center provides the most extensive and most in-depth analysis of metabolites available today, using a range of validated protocols for fee-for-service projects and scientific collaborations.
Professor Fiehn’s research aims at understanding metabolism on a comprehensive level in human population cohorts, animal and plant models, and cells and microorganisms. In order to leverage data from these diverse sets of biological systems, his research laboratory focuses on standardizing metabolomic reports and establishing metabolomic databases and libraries, for example the MassBank of North America that hosts over 200,000 public metabolite mass spectra and BinBase, a resource of over 90,000 samples covering more than 1,900 studies. Professor Fiehn’s laboratory members develop and implement new approaches and technologies in analytical chemistry for covering the metabolome, from increasing peak capacity by ion mobility to compound identifications through cheminformatics workflows and software. He collaborates with a range of investigators for interpreting metabolomic data in human diseases through statistics, text mining and pathway-based mapping efforts. He also studies fundamental biochemical questions from metabolite damage repair to the new concept of epimetabolites, the chemical transformation of primary metabolites that gain regulatory functions in cells.
For his work, Professor Fiehn has received a range of awards including the 2014 Molecular & Cellular Proteomics Lecture Award and the 2014 Metabolomics Society Lifetime Achievement Award. He served on the Board of Directors of the Metabolomics Society from 2005-2010 and 2012-2015, organizing a range of workshops and conferences, including the 2011 Asilomar metabolomics meeting and the 2015 Metabolomics Society international conference in San Francisco that reached a record of over 1,000 participants.
Professor Fiehn’s research aims at understanding metabolism on a comprehensive level in human population cohorts, animal and plant models, and cells and microorganisms. In order to leverage data from these diverse sets of biological systems, his research laboratory focuses on standardizing metabolomic reports and establishing metabolomic databases and libraries, for example the MassBank of North America that hosts over 200,000 public metabolite mass spectra and BinBase, a resource of over 90,000 samples covering more than 1,900 studies. Professor Fiehn’s laboratory members develop and implement new approaches and technologies in analytical chemistry for covering the metabolome, from increasing peak capacity by ion mobility to compound identifications through cheminformatics workflows and software. He collaborates with a range of investigators for interpreting metabolomic data in human diseases through statistics, text mining and pathway-based mapping efforts. He also studies fundamental biochemical questions from metabolite damage repair to the new concept of epimetabolites, the chemical transformation of primary metabolites that gain regulatory functions in cells.
For his work, Professor Fiehn has received a range of awards including the 2014 Molecular & Cellular Proteomics Lecture Award and the 2014 Metabolomics Society Lifetime Achievement Award. He served on the Board of Directors of the Metabolomics Society from 2005-2010 and 2012-2015, organizing a range of workshops and conferences, including the 2011 Asilomar metabolomics meeting and the 2015 Metabolomics Society international conference in San Francisco that reached a record of over 1,000 participants.
