Crystal structure of truncated human apolipoprotein A-I suggests a lipid-bound conformation
Crystal structure of truncated human apolipoprotein A-I suggests a lipid-bound conformation
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DOI：
10.1073/pnas.94.23.12291
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发表时间：
1997-11-11
影响因子：
11.1
通讯作者：
Brouillette, CG
中科院分区：
文献类型：
--
作者：
Borhani, DW;Rogers, DP;Brouillette, CG
已在4埃分辨率下测定了截短的人载脂蛋白A-I（apoA-I）的结构，所述截短的人载脂蛋白A-I是高密度脂蛋白的主要蛋白组分。晶体包含apoA-I的残基44-243（外显子4），所述残基44-243是与完整的apoA-I类似地结合脂质的片段，并且即使在没有脂质的情况下也保持脂质结合构象，该分子几乎完全由假连续的两亲性铜螺旋组成，在规则间隔的脯氨酸残基处被扭结打断;它采用类似于尺寸为125 × 80 × 40埃的马蹄铁的形状，不对称单元中的四个分子通过它们的疏水表面缔合以形成具有椭圆环形状的反平行四螺旋束。基于这种结构，我们提出了一个模型的载脂蛋白A-I结合高密度脂蛋白的结构。
The structure of truncated human apolipoprotein A-I (apo A-I), the major protein component of high density lipoprotein, has been determined at 4-Angstrom resolution, The crystals comprise residues 44-243 (exon 4) of apo A-I, a fragment that binds to lipid similarly to intact apo A-I and that retains the lipid-bound conformation even in the absence of lipid, The molecule consists almost entirely of a pseudocontinuous, amphipathic cu-helix that is punctuated by kinks at regularly spaced proline residues; it adopts a shape similar to a horseshoe of dimensions 125 x 80 x 40 Angstrom, Four molecules in the asymmetric unit associate via their hydrophobic faces to form an antiparallel four-helix bundle with an elliptical ring shape. Based on this structure, we propose a model for the structure of apo A-I bound to high density lipoprotein.