Structure similarity, difference and variability in the filamentous viruses fd, If1, IKe, Pf1 and Xf. Investigation by laser Raman spectroscopy.
Structure similarity, difference and variability in the filamentous viruses fd, If1, IKe, Pf1 and Xf. Investigation by laser Raman spectroscopy.
复制标题
丝状病毒 fd、If1、IKE、Pf1 和 Xf 的结构相似性、差异和变异性。
DOI：
10.1016/s0022-2836(83)80260-5
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发表时间：
1983
影响因子：
5.6
通讯作者：
Day,LA
中科院分区：
文献类型：
--
作者：
ThomasJr,GJ;Prescott,B;Day,LA
用激光拉曼差谱研究了丝状噬菌体fd、If 1、IKe、Pf 1、Xf和Pf 3在低、中、高离子强度水溶液中的温度变化。通过与已知结构的模型化合物和病毒的拉曼光谱进行类比，数据揭示了以下结构特征：每种病毒外壳蛋白亚基的主要二级结构是α-螺旋，但α-螺旋的量因病毒而异，从Pf 1中估计的100%到Xf中估计的约50%。酪氨酸、色氨酸和苯丙氨酸残基的分子环境和分子间相互作用在不同的病毒中不同，脂肪族氨基酸侧链的构象也不同。外壳蛋白结构的上述特征对Na+浓度、温度或两者的变化高度敏感。A-DNA和B-DNA结构的骨架在任何一种病毒中都没有出现，并且所有六种病毒都显示出不寻常的DNA结构。Pf 1的α-螺旋蛋白亚基与Pf 3和Xf一样，可以可逆地转变为β-折叠结构，同时保持与DNA的结合;然而fd、IKe和If 1不经历这种转变。拉曼强度随离子强度或温度的变化表明，脂肪族氨基酸侧链的反式旋转和芳香族侧链的堆积是每种病毒的重要结构变量。
The filamentous bacteriophages fd, If1, IKe, Pf1, Xf and Pf3 in aqueous solutions of low, moderate and high ionic strength have been investigated as a function of temperature by laser Raman difference spectroscopy. By analogy with Raman spectra of model compounds and viruses of known structure, the data reveal the following structural features: the predominant secondary structure of the coat protein subunit in each virus is the α-helix, but the amount of α-helix differs from one virus to another, ranging from an estimated high of 100% in Pf1 to a low of approximately 50% in Xf. The molecular environment and intermolecular interactions of tyrosine, tryptophan and phenylalanine residues differ among the different viruses, as do the conformations of aliphatic amino acid side-chains. The foregoing features of coat protein structure are highly sensitive to changes in Na+concentration, temperature or both. The backbones ofA-DNA andB-DNA structures do not occur in any of the viruses, and unusual DNA structures are indicated for all six viruses. The α-helical protein subunits of Pf1, like those of Pf3 and Xf, can undergo reversible transitions to β-sheet structures while retaining their association with DNA; yet fd, IKe and If1 do not undergo such transitions. Raman intensity changes with ionic strength or temperature suggest thattrans-gaucherotations of aliphatic amino acid side-chains and stacking of aromatic side-chains are important structural variables in each virus.