title: Comparative proteomic profiling of plasma very-low-density and low-density lipoproteins.
abstract: BACKGROUND
  Low-density lipoprotein (LDL) is a natural metabolite of very-low-density lipoprotein (VLDL) in the circulation. Systematic investigation of total protein components and dynamics might provide insights into this normal metabolic process.
  
  
  METHODS
  VLDL and LDL were purified from normolipidemia pooled plasma by gradient ultracentrifugation with either ionic or non-ionic media. The protein contents were compared by liquid chromatography tandem mass analyses based on isobaric tag for relative and absolute quantitation and two-dimensional gel electrophoresis.
  
  
  RESULTS
  Our comparative lipoproteomes revealed 21 associated proteins. Combined with Western blot analysis, and on the basis of the differential expression levels we classified them into 3 groups: (i) VLDL>LDL [apolipoprotein (apo) A-IV, apo(a), apoCs, apoE, apoJ and serum amyloid A-4]; (ii) VLDL<LDL [albumin, alpha-1-antitrypsin, apoD, apoF, apoM, and paraoxonase-1]; and (iii) VLDL=LDL [apoA-I, apoA-II, apoB-100, apoL-I and prenylcysteine oxidase-1]. The apoA-I level positively correlated with PCYOX1 but negatively with apoM in VLDL and LDL. Furthermore, the two-dimensional maps displayed 5 apoA-I isoforms in which phosphorylation at Ser55, Ser166, Thr185, Thr221 and Ser252 residues were identified.
  
  
  CONCLUSIONS
  This study revealed the VLDL- and LDL lipoproteomes and the full-spectrum protein changes during physiological VLDL-to-LDL transition. It provides a valuable dataset VLDL and LDL proteomes potentially applied to the development of diagnostics.
authors: Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors: Hung-Yu
authors: HY
authors: Sun
authors: Sun-Fang
authors: SF
authors: Chen
authors: Ming-Derg
authors: MD
authors: Lai
authors: Ting-Tsung
authors: TT
authors: Chang
authors: Tz-Li
authors: TL
authors: Chen
authors: Pei-Yu
authors: PY
authors: Li
authors: Dar-Bin
authors: DB
authors: Shieh
authors: Kung-Chia
authors: KC
authors: Young
mesh_terms: D000328:Adult; D015153:Blotting, Western; D002499:Centrifugation, Density Gradient; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D008297:Male; D040901:Proteomics; D012016:Reference Values; D053719:Tandem Mass Spectrometry
chemical_list: D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL