Solution structure of Pisum sativum defensin 1 by high resolution NMR:: Plant defensins, identical backbone with different mechanisms of action
Solution structure of Pisum sativum defensin 1 by high resolution NMR:: Plant defensins, identical backbone with different mechanisms of action
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DOI：
10.1006/jmbi.2001.5252
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发表时间：
2002-01-25
影响因子：
5.6
通讯作者：
Valente, AP
中科院分区：
文献类型：
--
作者：
Almeida, MS;Cabral, KMS;Valente, AP
Pisum sativum defensin 1 (Psd1) 是一种从豌豆种子中分离出来的 46 个氨基酸残基的植物防御素。 Psd1 溶液中的三维结构通过在 600 MHz 记录的二维 NMR 数据确定。实验约束用于使用 CNS 和扭转角分子动力学进行结构计算。选择 20 个最低能量结构并进一步进行最小化，主链的均方根偏差为 0.78(+/-0.22) 埃，分子所有原子的均方根偏差为 1.91(+/-0.60) 埃。该蛋白质具有球状折叠，具有三链反平行 β 折叠和 α 螺旋（从残基 Asn17 到 Leu27）。 Psd1 呈现所谓的“半胱氨酸稳定的 α/β 基序”，并在主链中呈现与其他防御素和神经毒素相同的三维拓扑结构。通过比较具有高三维（使用软件 TOP 和 DALI 选择）拓扑的蛋白质之间的静电表面电位，可以深入了解 Psd1 的作用模式。呈现抗真菌活性或钠通道抑制活性的蛋白质之间的表面拓扑结构是不同的。另一方面，表面拓扑呈现出钾通道抑制剂的几个共同特征，表明 Psd1 具有这种活性。发现了钾通道抑制剂的其他共同特征，包括存在抑制活性所必需的赖氨酸残基。与此处提出的策略相反，初级序列中 Psd1 的身份不足以推断作用机制。 (C) 2002 年学术出版社。
Pisum sativum defensin 1 (Psd1) is a 46 amino acid residue plant defensin isolated from seeds of pea. The three-dimensional structure in solution of Psd1 was determined by two-dimensional NMR data recorded at 600 MHz. Experimental restraints were used for structure calculation using CNS and torsion-angle molecular dynamics. The 20 lowest energy structures were selected and further subjected to minimization, giving a root-mean-square deviation of 0.78(+/-0.22) Angstrom in the backbone and 1.91(+/-0.60) Angstrom for over all atoms of the molecule. The protein has a globular fold with a triple-stranded antiparalell beta-sheet and an alpha-helix (from residue Asn17 to Leu27). Psd1 presents the so called "cysteine stabilized alpha/beta motif" and presents identical three-dimensional topology in the backbone with other defensins and neurotoxins. Comparison of the electrostatic surface potential among proteins with high three-dimensional (selected using the softwares TOP and DALI) topology gave insights into the mode of action of Psd1. The surface topologies between proteins that present antifungal activity or sodium channel inhibiting activity are different. On the other hand the surface topology presents several common features with potassium channel inhibitors, suggesting that Psd1 presents this activity. Other common features with potassium channel inhibitors were found including the presence of a lysine residue essential for inhibitory activity. The identity of Psd1 in primary sequence is not enough to infer a mechanism of action, in contrast with the strategy proposed here. (C) 2002 Academic Press.