Solution structure and backbone dynamics of human epidermal-type fatty acid-binding protein (E-FABP)
Solution structure and backbone dynamics of human epidermal-type fatty acid-binding protein (E-FABP)
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DOI：
10.1042/bj20020039
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发表时间：
2002-06-15
影响因子：
4.1
通讯作者：
Lücke, C
中科院分区：
文献类型：
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作者：
Gutiérrez-González, LH;Ludwig, C;Lücke, C
人表皮型脂肪酸结合蛋白（E-FABP）属于细胞内14-15 kDa脂质结合蛋白家族，其功能与脂肪酸信号传导、细胞生长、调节和分化有关。为了更好地理解其结构-功能关系，我们报道了其溶液结构和主链动力学的核磁共振谱特征。应用多维高分辨率核磁共振技术对未标记和N-15富集的重组人E-FABP进行了H-1和N-15共振赋值。基于2008年的距离限制。得到了人体E-FABP的三维溶液结构（主原子均方根偏差为0.92+/-0.11埃，其中1埃= 0.1 nm），主要由10条反平行的β -链组成β -桶状结构。在500、600和800 MHz的N-15弛豫实验（T-1、T-2和异核Overhauser效应）提供了蛋白质骨架内部动力学的信息。几乎所有非末端主链酰胺基团的序参数均为S-2 > 0.8，平均值为0.88 +/- 0.04，表明在纳秒-皮秒时间范围内主链迁移率均较低。此外，氢/氘交换实验表明，在毫秒至微秒的时间范围内，β -片结构中氢键网络的稳定性与构象交换之间存在直接关系。本研究阐述的E-FABP主干动力学特征与系统发育上密切相关的心脏型FABP以及与回肠脂质结合蛋白关系较远的回肠脂质结合蛋白的特征明显不同，这意味着E-FABP与整体蛋白质稳定性有很强的相互依赖性，也可能与脂质结合蛋白家族成员的配体结合亲和力有关。
Human epidermal-type fatty acid-binding protein (E-FABP) belongs to a family of intracellular 14-15 kDa lipid-binding proteins, whose functions have been associated with fatty acid signalling, cell growth, regulation and differentiation. As a contribution to understanding the structure-function relationship, we report in the present study features of its solution structure and backbone dynamics determined by NMR spectroscopy. Applying multi-dimensional high-resolution NMR techniques on unlabelled and N-15-enriched recombinant human E-FABP, the H-1 and N-15 resonance assignments were completed. On the basis of 2008 distance restraints. the three-dimensional solution structure of human E-FABP was subsequently obtained (backbone atom root-mean-square deviation of 0.92+/-0.11 Angstrom where 1 Angstrom = 0.1 nm), consisting mainly of 10 anti-parallel beta-strands that form a beta-barrel structure. N-15 relaxation experiments (T-1, T-2 and heteronuclear nuclear Overhauser effects) at 500, 600 and 800 MHz provided information on the internal dynamics of the protein backbone. Nearly all non-terminal backbone amide groups showed order parameters S-2 > 0.8, with an average value of 0.88 +/- 0.04, suggesting a uniformly low backbone mobility in the nanosecond-to-picosecond time range. Moreover, hydrogen/ deuterium exchange experiments indicated a direct correlation between the stability of the hydrogen-bonding network in the beta-sheet structure and the conformational exchange in the millisecond-to-microsecond time range. The features of E-FABP backbone dynamics elaborated in the present study differ markedly from those of the phylogenetically closely related heart-type FABP and the more distantly related ileal lipid-binding protein, implying a strong interdependence with the overall protein stability and possibly also with the ligand-binding affinity for members of the lipid-binding protein family.