Structural basis of non-specific lipid binding in maize lipid-transfer protein complexes revealed by high-resolution X-ray crystallography
Structural basis of non-specific lipid binding in maize lipid-transfer protein complexes revealed by high-resolution X-ray crystallography
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DOI：
10.1006/jmbi.2001.4559
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发表时间：
2001-04-27
影响因子：
5.6
通讯作者：
Suh, SW
中科院分区：
文献类型：
--
作者：
Han, GW;Lee, JY;Suh, SW
非特异性脂转移蛋白(NsLTP)参与磷脂、糖脂、脂肪酸和类固醇在膜之间的运动。用X射线结晶学和核磁共振方法确定了植物nsLTPs的几种结构。然而，nsLTPs与疏水配体非特异性结合的详细结构基础仍然知之甚少。为了更好地了解nsLTPs与疏水配体非特异性结合的结构基础，并研究nsLTPs中脂肪酸结合腔的可塑性，测定了7个高分辨(1.3埃至1.9埃)晶体结构。这些描述了玉米幼苗中的nsLTP与一系列脂肪酸的络合物。通过对玉米nsLTP与不同配体的络合物结构的详细比较，揭示了nsLTP-油酸络合物中一种新的结合模式，这是以前没有见过的。此外，在CAPRATE复合体中，配体以相等的两个方向与蛋白质腔结合。玉米nsLTP中疏水空腔的体积随结合配体的大小而变化，配体结合空腔的结构可塑性以及非特异性van der Waals与疏水尾巴的相互作用占主导地位。为玉米nsLTP的非特异性提供了结构上的解释。疏水空腔容纳了从C10到CIA的各种配体。C18：1蓖麻油酸酯与Ala68的羟基氢键可能模拟了具有生物学意义的角蛋白单体结合。人血清白蛋白中的一些肉豆蔻酸结合部位类似于玉米的nsLTP，这意味着螺旋束在调节脂肪酸的非特异性结合方面具有重要意义。(C)2001年学术出版社。
Non-specific lipid-transfer proteins (nsLTPs) are involved in the movement of phospholipids, glycolipids, fatty acids, and steroids between membranes. Several structures of plant nsLTPs have been determined both by X-ray crystallography and nuclear magnetic resonance. However, the detailed structural basis of the non-specific binding of hydrophobic ligands by nsLTPs is still poorly understood. In order to gain a better understanding of the structural basis of the non-specific binding of hydrophobic ligands by nsLTPs and to investigate the plasticity of the fatty acid binding cavity in nsLTPs, seven high-resolution (between 1.3 Angstrom and 1.9 Angstrom) crystal structures have been determined. These depict the nsLTP from maize seedlings in complex with an array of fatty acids.A detailed comparison of the structures of maize nsLTP in complex with various ligands reveals a new binding mode in an nsLTP-oleate complex which has not been seen before. Furthermore, in the caprate complex, the ligand binds to the protein cavity in two orientations with equal occupancy. The volume of the hydrophobic cavity in the nsLTP from maize shows some variation depending on the size of the bound ligands.The structural plasticity of the ligand binding cavity and the predominant involvement of non-specific van der Waals interactions with the hydrophobic tail. of the ligands provide a structural explanation for the non-specificity of maize nsLTP. The hydrophobic cavity accommodates various ligands from C10 to Cia. The C18:1 ricinoleate with its hydroxyl group hydrogen bonding to Ala68 possibly mimics cutin monomer binding which is Of biological importance. Some of the myristate binding sites in human serum albumin resemble the maize nsLTP, implying the importance of a helical bundle in accommodating the non-specific binding of fatty acids. (C) 2001 Academic Press.