title: ¹⁵N metabolic labeling: evidence for a stable isotope effect on plasma protein levels and peptide chromatographic retention times.
abstract: Many quantitative proteomics methods rely on protein and peptide labeling with stable isotopes. We have recently found that the introduction of ¹⁵N into organisms via in vivo metabolic labeling affects protein expression levels as well as metabolic pathways and behavioral phenotypes. Here, we present further evidence for a stable isotope effect based on the plasma proteome analysis of ¹⁵N-labeled mice. We compared plasma proteomes of ¹⁵N-labeled and unlabeled (¹⁴N) mice by quantitative MS. We found a number of protein level differences, some of which were verified immunochemically. In addition, we observed divergent chromatographic retention time and peak full width at half maximum (FWHM) between ¹⁵N-labeled and ¹⁴N tryptic peptides. Our data point toward a systemic effect of the introduction of heavy isotopes in vivo.
authors.affiliation: Proteomics and Biomarkers, Max Planck Institute of Psychiatry, Munich, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Webhofer
authors.forename: Yaoyang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jan
authors.initials: J
authors.lastname: Brusis
authors.forename: Stefan
authors.initials: S
authors.lastname: Reckow
authors.forename: Rainer
authors.initials: R
authors.lastname: Landgraf
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Maccarrone
authors.forename: Christoph W
authors.initials: CW
authors.lastname: Turck
authors.forename: Michaela D
authors.initials: MD
authors.lastname: Filiou
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005786:Gene Expression Regulation; D007553:Isotope Labeling / Q000379:methods*; D051379:Mice; D009587:Nitrogen Isotopes / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D020543:Proteome / Q000737:chemistry / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*
chemical_list: D001798:Blood Proteins; D009587:Nitrogen Isotopes; D010455:Peptides; D020543:Proteome
keywords: (15)N isotope effect; (15)N metabolic labeling; C5; FWHM; HAB; Mup; Plasma; Quantitative proteomics; Serpina6; TPP; TST; XIC; complement 5; corticosteroid-binding globulin; extracted ion chromatogram; full width at half maximum; high anxiety-related behavior; major urinary protein; tail suspension test; trans-proteomic pipeline