HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Forte, T. M. Articles by McCall, M. R. Search for Related Content PubMed PubMed Citation Articles by Forte, T. M. Articles by McCall, M. R. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol 37, 1076-1085, Copyright © 1996 by Lipid Research, Inc.

ARTICLES

Structural relationships between nascent apoA-I-containing particles that are extracellularly assembled in cell culture

TM Forte, JK Bielicki, L Knoff and MR McCall
Department of Molecular and Nuclear Medicine, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

Apolipoprotein A-I (apoA-I) incubated with CHO cells assembles three major nascent lipid complexes with diameters of 7.3, 9, and 11 nm. Previous studies suggested that the smaller nascent particles were precursors for the larger nascent ones. To test this hypothesis, the 7.3, 9, and 11 nm apoA-I-lipid complexes formed by incubating CHO cells with lipid-free apoA-I were isolated and subsequently each subpopulation was re-incubated with cells in the absence of other subpopulations. The physical-chemical characteristics of each subpopulation were examined before and after re-incubation in an effort to understand relationships. if any, between the different nascent complexes. The 7.3, 9, and 11 nm complexes were unique in that each of the particles had pre-alpha mobility on agarose gels: this rapid migration was not altered by re-incubation with cells. Protein crosslinking studies indicated that the 7.3, 9, and 11 nm complexes possessed 2, 3, and 4 apoA-I molecules per complex, respectively; it is unlikely that the size of the particle and number of apoA-I molecules per particle played a role in the increased negative charge of the particles. The present study shows that smaller particles did not give rise to larger ones upon re-incubation with cells. Rather, the 11 and 9 nm particles both generated smaller discs (the 11 nm giving rise primarily to 9 nm discs and the 9 nm complex giving rise to 7.3 nm discs) suggesting that, during incubation with cells, the complexes are destabilized and remodeled into smaller, not larger, complexes. Surprisingly, the 7.3 nm complexes during re-incubation with cells were extremely stable and did not undergo size alteration. When the 7.3 nm particles were incubated with additional small quantities of lipid-free apoA-I (1-2 microgram/ml), larger discoidal complexes were generated suggesting that the formation of larger particles may be driven by the availability of lipid-free apoA-I.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				S. Yokoyama Assembly of High-Density Lipoprotein Arterioscler. Thromb. Vasc. Biol., January 1, 2006; 26(1): 20 - 27. [Abstract] [Full Text] [PDF]

				L. Krimbou, H. Hajj Hassan, S. Blain, S. Rashid, M. Denis, M. Marcil, and J. Genest Biogenesis and speciation of nascent apoA-I-containing particles in various cell lines J. Lipid Res., August 1, 2005; 46(8): 1668 - 1677. [Abstract] [Full Text] [PDF]

				K.-A. Rye and P. J. Barter Formation and Metabolism of Prebeta-Migrating, Lipid-Poor Apolipoprotein A-I Arterioscler. Thromb. Vasc. Biol., March 1, 2004; 24(3): 421 - 428. [Abstract] [Full Text]

				J. W. Chisholm, E. R. Burleson, G. S. Shelness, and J. S. Parks ApoA-I secretion from HepG2 cells: evidence for the secretion of both lipid-poor apoA-I and intracellularly assembled nascent HDL J. Lipid Res., January 1, 2002; 43(1): 36 - 44. [Abstract] [Full Text] [PDF]

				J. K. Bielicki, M. R. McCall, L. J. Stoltzfus, A. Ravandi, A. Kuksis, E. M. Rubin, and T. M. Forte Evidence That Apolipoprotein A-IMilano Has Reduced Capacity, Compared With Wild-Type Apolipoprotein A-I, to Recruit Membrane Cholesterol Arterioscler. Thromb. Vasc. Biol., September 1, 1997; 17(9): 1637 - 1643. [Abstract] [Full Text]