ABCMdb

PMID: 23990662

Fotakis P, Kateifides AK, Gkolfinopoulou C, Georgiadou D, Beck M, Grundler K, Chroni A, Stratikos E, Kardassis D, Zannis VI
Role of the hydrophobic and charged residues in the 218-226 region of apoA-I in the biogenesis of HDL.
J Lipid Res. 2013 Dec;54(12):3281-92. doi: 10.1194/jlr.M038356. Epub 2013 Aug 29., [PubMed]

Sentences

No. Mutations Sentence Comment

7 ABCA1 p.Leu222Ala Adenovirus-mediated gene transfer of apoA-I[L218A/ L219A/V221A/L222A] in apoA-I d1a;/d1a; mice decreased plasma cholesterol and apoA-I levels to 15% of wild-type (WT) control mice and generated pre-beta-and ॷ4-HDL particles. Login to comment 21 ABCA1 p.Leu222Ala Published, JLR Papers in Press, August 29, 2013 DOI 10.1194/jlr.M038356 Role of the hydrophobic and charged residues in the 218-226 region of apoA-I in the biogenesis of HDL 1 Panagiotis Fotakis,* ,ߤ Andreas K. Kateifides,* ,ߤ Christina Gkolfinopoulou, &#a7; Dimitra Georgiadou, &#a7; Melissa Beck,* ,ߤ Katharina Gr&#fc;ndler,* Angeliki Chroni, &#a7; Efstratios Stratikos, &#a7; Dimitris Kardassis, ߤ and Vassilis I. Zannis 2, * Whitaker Cardiovascular Institute,* Boston University School of Medicine, Boston, MA 02118; Department of Biochemistry,ߤ University of Crete Medical School, Heraklion, Crete, Greece 71110; and National Center for Scientific Research "Demokritos",&#a7; Athens, Greece 15310 Abbreviations: ANS, 8-anilino-1-naphthalene-sulfonate; apoA-I[218-222], the apoA-I carrying the L218A/L219A/V221A/L222A mutations; apoA-I[E223A/K226A], the apoA-I carrying the E223A/K226A mutations apoA-I afa;/afa; , apoA-I-deficient; apoA-I afa;/afa; &#d7; apoE afa;/afa; , apoA-I and apoE double-deficient; CD, circular dichroism; cpt-cAMP, 8-(4-chlorophenylthio) adenosine 3':5'-cyclic monophosphatase; DMPC, dimyristoyl-L-ॷ- phosphatidylcholine; EM, electron microscopy; FPLC, fast-protein liquid chromatography; GdnHCl, guanidine hydrochloride; HEK293, human embryonic kidney 293; HTB-13, SW 1783 human astrocytoma; pfu, plaque-forming unit; POPC, beta-oleoyl-ॹ-palmitoyl-L-ॷ-phosphatidylcholine; rHDL, reconstituted HDL; WMF, wavelength of maximum fluorescence; WT, wild-type. Login to comment 60 ABCA1 p.Leu222Ala In addition to the drastic effect of the L218A/L219A/ V221A/L222A mutations on the biogenesis of HDL, the mutants also inhibited the ability of lipid-free apoA-I to promote transendothelial transport (20), as well as its bactericidal activity against Gram-negative bacteria (21), indicating the importance of the 218-222 residues for the functions of apoA-I. Login to comment 74 ABCA1 p.Leu222Ala The L218A/L219A/V221A/L222A mutations in apoA-I resulted in a great increase in plasma apoA-IV that floated in the IDL/LDL/HDL2/HDL3 region (Fig. 3D and supplementary Fig. II) and the presence of apoB-48 in the HDL region (Fig. 3E). Login to comment 132 ABCA1 p.Leu222Ala Effect of the L218A/L219A/V221A/L222A and E223A/ K226A mutations on the ॷ-helical content, thermal unfolding, chemical unfolding, and hydrophobic surface exposure of apoA-I To test whether the functional changes of the two apoA-I mutants are accompanied by changes in the structure and conformation of the protein, we used an array of biophysical assays to evaluate the effects of these mutations (Fig. 6). Login to comment 142 ABCA1 p.Leu222Ala L218A/L219A/V221A/L222A and E223A/K226A mutations alter the functional and physicochemical properties of apoA-I The in vitro experiments showed that, compared with WT apoA-I, the capacity of the apoA-I[218-222] mutant to promote ABCA1-mediated cholesterol efflux and to activate LCAT was 20% and 66%, respectively. Login to comment 173 ABCA1 p.Leu222Ala Calculated biophysical parameters for WT and mutant apoA-I forms Mutation Circular Dichroism Thermal Denaturation Chemical Denaturation ANS Binding ApoA-I ॷ-Helix Tm (&#b0;C) Slope Cooperativity Index (n) èc;H (kcal/mol) èc;GD o (kcal/mol) D1/2 (M) mc (kcal mol afa;2 ) Fold Increasea WT 60.0 &#b1; 1.5 55.6 &#b1; 0.4 8.3 &#b1; 0.4 6.4 &#b1; 0.2 25.9 &#b1; 1.5 6.3 &#b1; 0.4 1.01 &#b1; 0.02 6.3 &#b1; 0.4 6.0 &#b1; 0.4 L218A/L219A/V221A/L222A 52.7 &#b1; 1.6b 56.1 &#b1; 0.8 4.6 &#b1; 0.2 b 9.7 &#b1; 0.6 b 46.4 &#b1; 2.4 b 6.6 &#b1; 0.4 1.00 &#b1; 0.03 6.4 &#b1; 0.4 3.5 &#b1; 0.2 b E223A/K226A 55.8 &#b1; 1.1 c 53.4 &#b1; 0.2 b 10.4 &#b1; 1.4 d 5.3 &#b1; 0.7 b 21.01 &#b1; 2.2 e 2.5 &#b1; 0.2 b 0.88 &#b1; 0.02 f 2.8 &#b1; 0.1 b 9.6 &#b1; 0.5 b Values are means &#b1; SD from three or four experiments. Login to comment