Abstract: We compared the protein/lipid structure and Ch-nucleating capacity of individual lipid carriers in two groups of human gallbladder biles: 11 with Fast cholesterol nucleation (2.2 +/- 1.3 days) and 10 with Slow cholesterol nucleation (19.2 +/- 4.4 days). The groups had comparable cholesterol-saturation (1.31 vs. 1.28), total lipids (9.9 vs. 8.5 g/dI) and proteins (8.5 vs. 7.6 mg/ml). Bile was ultracentrifuged (2 h at 150 000 x g) and the resulting isotropic phase was incubated with [H-3]Ch and [C-14]lecithin and gel-chromatographed on a Superose 6 column with a buffer containing 7.0 mM sodium-taurocholate. Seven protein peaks were identified (280 nm and biochemistry), with the following molecular mass ranges (kDa): 1 (Void volume), 2 (155-205), 3 (50-79), 4 (20-29), 5 (6-15), 6 (3.5-6), 7 (2-3.5). Peaks 2 and 3 were identified as vesicles and micelles, respectively. Fast vs. Slow Ch nucleating biles had: (a) more (P < 0.02) cholesterol coeluting with vesicles, (b) more (P < 0.01) lecithin coeluting with low m.w. peaks (Nos. 5-6), (c) less (P < 0.01) cholesterol and lecithin coeluting with micelles. An inverse correlation (P < 0.001) was observed between the amount of proteins coeluting with the micellar peak and the cholesterol nucleation of both whole bile and isolated micellar fractions. A marked shift of cholesterol and lecithin from micelles to vesicles was apparent, in the whole bile, after cholesterol nucleation had occurred. Incubation and sequential analysis of isolated and radiolabeled micelles showed a progressive transfer of lecithin and cholesterol molecules to low molecular weight fractions and to vesicles before cholesterol nucleation. We conclude that pro-nucleating biliary vesicles develop from micelles, due to the phasing out and redistribution of micellar cholesterol and lecithin, which are probably induced by biliary proteins.

Differential patterns of lipid-protein association in fast and slow cholesterol nucleating human gallbladder biles: implications for cholesterol nucleation from biliary lipid carriers / GINANNI CORRADINI, Stefano; Alvaro, Domenico; L., Giacomelli; M., Cedola; M., Angelico. - In: BIOCHIMICA ET BIOPHYSICA ACTA. - ISSN 0006-3002. - STAMPA. - 1086:1(1991), pp. 125-133. [10.1016/0005-2760(91)90163-C]

Differential patterns of lipid-protein association in fast and slow cholesterol nucleating human gallbladder biles: implications for cholesterol nucleation from biliary lipid carriers.

GINANNI CORRADINI, Stefano;ALVARO, Domenico;
1991

Abstract

Abstract: We compared the protein/lipid structure and Ch-nucleating capacity of individual lipid carriers in two groups of human gallbladder biles: 11 with Fast cholesterol nucleation (2.2 +/- 1.3 days) and 10 with Slow cholesterol nucleation (19.2 +/- 4.4 days). The groups had comparable cholesterol-saturation (1.31 vs. 1.28), total lipids (9.9 vs. 8.5 g/dI) and proteins (8.5 vs. 7.6 mg/ml). Bile was ultracentrifuged (2 h at 150 000 x g) and the resulting isotropic phase was incubated with [H-3]Ch and [C-14]lecithin and gel-chromatographed on a Superose 6 column with a buffer containing 7.0 mM sodium-taurocholate. Seven protein peaks were identified (280 nm and biochemistry), with the following molecular mass ranges (kDa): 1 (Void volume), 2 (155-205), 3 (50-79), 4 (20-29), 5 (6-15), 6 (3.5-6), 7 (2-3.5). Peaks 2 and 3 were identified as vesicles and micelles, respectively. Fast vs. Slow Ch nucleating biles had: (a) more (P < 0.02) cholesterol coeluting with vesicles, (b) more (P < 0.01) lecithin coeluting with low m.w. peaks (Nos. 5-6), (c) less (P < 0.01) cholesterol and lecithin coeluting with micelles. An inverse correlation (P < 0.001) was observed between the amount of proteins coeluting with the micellar peak and the cholesterol nucleation of both whole bile and isolated micellar fractions. A marked shift of cholesterol and lecithin from micelles to vesicles was apparent, in the whole bile, after cholesterol nucleation had occurred. Incubation and sequential analysis of isolated and radiolabeled micelles showed a progressive transfer of lecithin and cholesterol molecules to low molecular weight fractions and to vesicles before cholesterol nucleation. We conclude that pro-nucleating biliary vesicles develop from micelles, due to the phasing out and redistribution of micellar cholesterol and lecithin, which are probably induced by biliary proteins.
1991
BILIARY LIPID PROTEIN ASSOCIATION, CHOLESTEROL NUCLEATION TIME, (HUMAN BILE)
01 Pubblicazione su rivista::01a Articolo in rivista
Differential patterns of lipid-protein association in fast and slow cholesterol nucleating human gallbladder biles: implications for cholesterol nucleation from biliary lipid carriers / GINANNI CORRADINI, Stefano; Alvaro, Domenico; L., Giacomelli; M., Cedola; M., Angelico. - In: BIOCHIMICA ET BIOPHYSICA ACTA. - ISSN 0006-3002. - STAMPA. - 1086:1(1991), pp. 125-133. [10.1016/0005-2760(91)90163-C]
File allegati a questo prodotto
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/107803
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 7
  • ???jsp.display-item.citation.isi??? 7
social impact