Secondary structure of human apolipoprotein A‐I(1–186) in lipid‐mimetic solution

FEBS Letters

Cushley, Robert J.²  Marcel, Yves L.¹  Frank, Philippe G.¹  Okon, Mark² 

[1] Lipoproteins and Atherosclerosis Research Group, University of Ottawa Heart Institute, Ottawa, Ont., Canada K1Y 4E9;Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, B.C., Canada V5A 1S6

关键词: Protein structure;    Apolipoprotein;    NMR;    Chemical shift index;    TALOS;    SDS;    apo;    apolipoprotein;    HDL;    high density lipoprotein(s);    VLDL;    very low density lipoprotein(s);    LCAT;    lecithin:cholesterol acyltransferase;    CD;    circular dichroism;    SDS;    sodium dodecyl sulfate;    NOESY;    nuclear Overhauser enhancement spectroscopy;    HSQC;    heteronuclear single quantum coherence;    CT;    constant time;    CSI;    chemical shift index;    TALOS;    torsion angle likelihood obtained from shift and sequence similarity;   

DOI  :  10.1016/S0014-5793(00)02375-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The solution structure of an apoA-I deletion mutant, apoA-I(1–186) was determined by the chemical shift index (CSI) method and the torsion angle likelihood obtained from shift and sequence similarity (TALOS) method, using heteronuclear multidimensional NMR spectra of [u-¹³C, u-¹⁵N, u-50% ²H]apoA-I(1–186) in the presence of sodium dodecyl sulfate (SDS). The backbone resonances were assigned from a combination of triple-resonance data (HNCO, HNCA, HN(CO)CA, HN(CA)CO and HN(COCA)HA), and intraresidue and sequential NOEs (three-dimensional (3D) and four-dimensional (4D) ¹³C- and ¹⁵N-edited NOESY). Analysis of the NOEs, H^α, C^α and C′ chemical shifts shows that apoA-I(1–186) in lipid-mimetic solution is composed of α-helices (which include the residues 8–32, 45–64, 67–77, 83–87, 90–97, 100–140, 146–162, and 166–181), interrupted by short irregular segments. There is one relatively long, irregular and mostly flexible region (residues 33–44), that separates the N-terminal domain (residues 1–32) from the main body of protein. In addition, we report, for the first time, the structure of the N-terminal domain of apoA-I in a lipid-mimetic environment. Its structure (α-helix 8–32 and flexible linker 33–44) would suggest that this domain is structurally, and possibly functionally, separated from the other part of the molecule.

【 授权许可】

Unknown