3s84

Publication Abstract from PubMed

Apolipoproteins are key structural elements of lipoproteins and critical mediators of lipid metabolism. Their detergent-like properties allow them to emulsify lipid or exist in a soluble lipid-free form in various states of self-association. Unfortunately, these traits have hampered high-resolution structural studies needed to understand the biogenesis of cardioprotective high-density lipoproteins (HDLs). We derived a crystal structure of the core domain of human apolipoprotein (apo)A-IV, an HDL component and important mediator of lipid absorption. The structure at 2.4 A depicts two linearly connected 4-helix bundles participating in a helix swapping arrangement that offers a clear explanation for how the protein self-associates as well as clues to the structure of its monomeric form. This also provides a logical basis for antiparallel arrangements recently described for lipid-containing particles. Furthermore, we propose a "swinging door" model for apoA-IV lipid association.

The Structure of Dimeric Apolipoprotein A-IV and Its Mechanism of Self-Association.,Deng X, Morris J, Dressmen J, Tubb MR, Tso P, Jerome WG, Davidson WS, Thompson TB Structure. 2012 May 9;20(5):767-79. PMID:22579246^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.