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

J. Biol. Chem., Vol. 281, Issue 13, 8871-8876, March 31, 2006

This Article Full Text Full Text (PDF) All Versions of this Article: 281/13/8871    most recent M507657200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend 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 Ledford, A. S. Articles by Shelness, G. S. Search for Related Content PubMed PubMed Citation Articles by Ledford, A. S. Articles by Shelness, G. S. Social Bookmarking                      What's this?

Self-association and Lipid Binding Properties of the Lipoprotein Initiating Domain of Apolipoprotein B^*

Aubrey S. Ledford¹, Richard B. Weinberg^¶, Victoria R. Cook, Roy R. Hantgan^||, and Gregory S. Shelness²

From the Departments of Pathology, Internal Medicine, ^¶Physiology & Pharmacology, and ^||Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1040

The amino-terminal 20.1% of apolipoprotein B (apoB20.1; residues 1-912) is sufficient to initiate and direct the formation of nascent apoB-containing lipoprotein particles. To investigate the mechanism of initial lipid acquisition by apoB, we examined the lipid binding and interfacial properties of a carboxyl-terminal His₆-tagged form of apoB20.1 (apoB20.1H). ApoB20.1H was expressed in Sf9 cells and purified by nickel affinity chromatography. ApoB20.1H was produced in a folded state as characterized by formation of intramolecular disulfide bonds and resistance to chemical reduction. Dynamic light scattering in physiological buffer indicated that purified apoB20.1H formed multimers, which were readily dissociable upon the addition of nonionic detergent (0.1% Triton X-100). ApoB20.1H was incapable of binding dimyristoylphosphatidylcholine multilamellar vesicles, unless its multimeric structure was first disrupted by guanidine hydrochloride. However, apoB20.1H multimers spontaneously dissociated and bound to the interface of naked and phospholipid-coated triolein droplets. These data reveal that the initiating domain of apoB contains solvent-accessible hydrophobic sequences, which, in the absence of a hydrophobic lipid interface or detergent, engage in self-association. The high affinity of apoB20.1H for neutral lipid is consistent with the membrane binding and desorption model of apoB-containing lipoprotein assembly.

Received for publication, July 14, 2005 , and in revised form, December 7, 2005.

^* This work was supported by National Institutes of Health Grants HL49373 (to G. S. S.) and HL30897 (to R. B. W.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ Supported by a predoctoral fellowship from the American Heart Association, Mid-Atlantic Affiliate.

² To whom correspondence should be addressed: Department of Pathology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157. Tel.: 336-716-3282; Fax: 336-716-6279; E-mail: gshelnes{at}wfubmc.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				J. R. Burnett, S. Zhong, Z. G. Jiang, A. J. Hooper, E. A. Fisher, R. S. McLeod, Y. Zhao, P. H. R. Barrett, R. A. Hegele, F. M. van Bockxmeer, et al. Missense Mutations in APOB within the beta{alpha}1 Domain of Human APOB-100 Result in Impaired Secretion of ApoB and ApoB-containing Lipoproteins in Familial Hypobetalipoproteinemia J. Biol. Chem., August 17, 2007; 282(33): 24270 - 24283. [Abstract] [Full Text] [PDF]

				J. A. Beckstead, K. Wong, V. Gupta, C.-P. L. Wan, V. R. Cook, R. B. Weinberg, P. M. M. Weers, and R. O. Ryan The C Terminus of Apolipoprotein A-V Modulates Lipid-binding Activity J. Biol. Chem., May 25, 2007; 282(21): 15484 - 15489. [Abstract] [Full Text] [PDF]