title: Multiple apolipoprotein kinetics measured in human HDL by high-resolution/accurate mass parallel reaction monitoring.
abstract: Endogenous labeling with stable isotopes is used to study the metabolism of proteins in vivo. However, traditional detection methods such as GC/MS cannot measure tracer enrichment in multiple proteins simultaneously, and multiple reaction monitoring MS cannot measure precisely the low tracer enrichment in slowly turning-over proteins as in HDL. We exploited the versatility of the high-resolution/accurate mass (HR/AM) quadrupole Orbitrap for proteomic analysis of five HDL sizes. We identified 58 proteins in HDL that were shared among three humans and that were organized into five subproteomes according to HDL size. For seven of these proteins, apoA-I, apoA-II, apoA-IV, apoC-III, apoD, apoE, and apoM, we performed parallel reaction monitoring (PRM) to measure trideuterated leucine tracer enrichment between 0.03 to 1.0% in vivo, as required to study their metabolism. The results were suitable for multicompartmental modeling in all except apoD. These apolipoproteins in each HDL size mainly originated directly from the source compartment, presumably the liver and intestine. Flux of apolipoproteins from smaller to larger HDL or the reverse contributed only slightly to apolipoprotein metabolism. These novel findings on HDL apolipoprotein metabolism demonstrate the analytical breadth and scope of the HR/AM-PRM technology to perform metabolic research.
authors: Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Division Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors: Sasha A
authors: SA
authors: Singh
authors: Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, MA.
authors: Allison B
authors: AB
authors: Andraski
authors: Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Division Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors: Brett
authors: B
authors: Pieper
authors: Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Division Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors: Wilson
authors: W
authors: Goh
authors: School of Medicine, Universidad de los Andes, Bogota, Colombia.
authors: Carlos O
authors: CO
authors: Mendivil
authors: Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, MA Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA maikawa@rics.bwh.harvard.edu fsacks@hsph.harvard.edu.
authors: Frank M
authors: FM
authors: Sacks
authors: Center for Interdisciplinary Cardiovascular Sciences, Cardiovascular Division Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA maikawa@rics.bwh.harvard.edu fsacks@hsph.harvard.edu.
authors: Masanori
authors: M
authors: Aikawa
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D002318:Cardiovascular Diseases / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D008075:Lipoproteins, HDL / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D010316:Particle Size; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D012307:Risk Factors
chemical_list: D008075:Lipoproteins, HDL; D010446:Peptide Fragments
keywords: compartmental modeling; coronary heart disease; mass spectrometry; metabolism; size fractionation