title: Proteomic analysis of human very low-density lipoprotein by two-dimensional gel electrophoresis and MALDI-TOF/TOF.
abstract: Biochemical studies of lipoproteins have shed light on their composition, highly contributing to the comprehension of their function. Due to the complexity of their structure, however, an in-depth structural analysis, in terms of components and PTMs, may still unravel important players in physiological and pathological processes of lipid metabolism. In this study, we performed a protein map of very low-density lipoprotein (VLDL) using a 2-DE MALDI-TOF/TOF proteomic approach. Several VLDL-associated apolipoproteins were identified, including five isoforms of apoE, three isoforms of apoC-IV, and one isoform each of apoC-III, apoM, apoA-I, and apoA-IV. Notably, we also identified seven isoforms of apoL-I and two isoforms of prenylcysteine lyase as new VLDL-associated proteins. Furthermore, we were able to identify PTM of apoE, which was found to be differently O-glycosylated at Thr212 residue, and PTM of apoL-I which we described, for the first time, to be phosphorylated at Ser296. While the physiological relevance of our finding remains to be assessed, we believe that our results will be useful as reference for future studies of VLDL structure in specific physiopathological conditions.
authors.affiliation: National Institute for Infectious Diseases L. Spallanzani, IRCCS, Rome, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Mancone
authors.forename: Laura
authors.initials: L
authors.lastname: Amicone
authors.forename: Gian Maria
authors.initials: GM
authors.lastname: Fimia
authors.forename: Elena
authors.initials: E
authors.lastname: Bravo
authors.forename: Mauro
authors.initials: M
authors.lastname: Piacentini
authors.forename: Marco
authors.initials: M
authors.lastname: Tripodi
authors.forename: Tonino
authors.initials: T
authors.lastname: Alonzi
mesh_terms: D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D008079:Lipoproteins, VLDL / Q000032:analysis* / Q000097:blood; D020033:Protein Isoforms / Q000032:analysis / Q000097:blood; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D008079:Lipoproteins, VLDL; D020033:Protein Isoforms