Abstract

GARDA, Horacio Alberto et al. Apolipoprotein A-I and high density lipoproteins: Structure and role in cellular cholesterol homeostasis. Acta bioquím. clín. latinoam. [online]. 2013, vol.47, n.2, pp.327-341. ISSN 0325-2957.

Apolipoprotein A-I (apoAI) is the major protein component of high density lipoprotein (HDL), whose serum level is inversely correlated with atherogenic risk. Antiatherogenic properties are largely attributed to its key role in reverse cholesterol transport (RCT), a process that removes cholesterol excess from peripheral tissues. ApoAI is an amphitropic protein that almost exclusively contains amphipathic a-helices, and presents a large conformational flexibility that is crucial for its functional cycle, in which it inter-converts into different states: free or bound to membranes, or into a lipoprotein complex variety of different sizes, compositions and morphologies. This report reviews the current knowledge of the structure and lipid interaction properties of apoAI, in relation with HDL biogenesis and function in RCT. In particular, focus is made on the apoAI configuration in discoidal HDL; as well as on the interaction with lipids, and the importance for cellular cholesterol efflux, of an amphipathic a-helix pair having a particular distribution of the charged residues and that locate at the center of the apoAI molecule.

Keywords : Apolipoprotein A-I; High density lipoproteins; Reverse cholesterol transport; Discoidal lipoproteins; Amphipathic a-helices; Lipid-protein interaction.

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