Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Arrangement of apolipoprotein A-I in reconstituted high-density lipoprotein disks: An alternative model based on fluorescence resonance energy transfer experiments
Autore:
Tricerri, MA; Agree, AKB; Sanchez, SA; Bronski, J; Jonas, A;
Indirizzi:
Univ Illinois, Coll Med, Dept Biochem, Fluorescence Dynam Lab, Urbana, IL 61801 USA Univ Illinois Urbana IL USA 61801 escence Dynam Lab, Urbana, IL 61801 USA Univ Illinois, Dept Math, Urbana, IL 61801 USA Univ Illinois Urbana IL USA 61801 linois, Dept Math, Urbana, IL 61801 USA
Titolo Testata:
BIOCHEMISTRY
fascicolo: 16, volume: 40, anno: 2001,
pagine: 5065 - 5074
SICI:
0006-2960(20010424)40:16<5065:AOAAIR>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
LECITHIN-CHOLESTEROL ACYLTRANSFERASE; RIBOSOMAL-PROTEIN L7/L12; APOA-I; BINDING-PROTEINS; BELT MODEL; MEMBRANE; COMPLEXES; HELICES; DOMAINS; EFFLUX;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Jonas, A Univ Illinois, Coll Med, Dept Biochem, Fluorescence Dynam Lab, 506 S Mathews Ave, Urbana, IL 61801 USA Univ Illinois 506 S Mathews Ave Urbana IL USA 61801 IL 61801 USA
Citazione:
M.A. Tricerri et al., "Arrangement of apolipoprotein A-I in reconstituted high-density lipoprotein disks: An alternative model based on fluorescence resonance energy transfer experiments", BIOCHEM, 40(16), 2001, pp. 5065-5074

Abstract

The folding and organization of apolipoprotein A-I (apoA-I) in discoidal, high-density lipoprotein (HDL) complexes with phospholipids are not yet completely resolved. For about 20 years, it was generally accepted that the amphipathic helices of apoA-I lie parallel to the acyl chains of the phospholipids ("picket fence" model). However, based on the X-ray crystal structureof a large, lipid-free fragment of apoA-I, a "belt model" was recently proposed. In this model, the helices of two antiparallel apoA-I molecules are extended in a circular arrangement and lie perpendicular to the phospholipid acyl chains. To obtain conclusive information on the spatial organizationof apoA-I in discoidal HDL, we engineered three separate cysteine mutants of apoA-I (D9C, A124C, A232C) for specific labeling with the fluorescence probes ALEXA-488 or ALEXA-546 (fluorescein and rhodamine derivatives). The labeled apoA-I was reconstituted into well-defined HDL complexes containing two molecules of protein and dipalmitoylphosphatidylcholine, and the complexes were used in three quantitative fluorescence resonance energy transfer (FRET) experiments to determine the distances between two specific sites inan HDL particle. Comparison of the distances measured by FRET (4.7-7.8 nm)with those predicted from the existing models indicated that neither the picket fence nor the belt model can account for the experimental results; rather, a hairpin folding of each apoA-I monomer with most helices perpendicular to the phospholipid acyl chains and a random head-to-tail and head-to-head arrangement of the two apoA-I molecules in the HDL particles are strongly suggested by the distance and lifetime data.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/04/20 alle ore 04:07:21