Secondary structure determination in proteins from deep (192-223-nm) ultraviolet Raman spectroscopy.
Secondary structure determination in proteins from deep (192-223-nm) ultraviolet Raman spectroscopy.
复制标题
通过深（192-223 nm）紫外拉曼光谱测定蛋白质的二级结构。
DOI：
10.1021/bi00382a011
复制
发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Spiro,TG
中科院分区：
文献类型：
--
作者：
Copeland,RA;Spiro,TG
普林斯顿大学化学系，普林斯顿，新泽西08544接收于1986年9月9日;修订后的Mandarin pt接收于1986年12月12日摘要：报告了无规卷曲聚赖氨酸的酰胺I、II、III和IF带在223、218、204、200和192 nm处用UV激光激发获得的拉曼强度。激发曲线显示通过-* 电子跃迁在~ 190 nm处增强。酰胺I的增强是弱的，但是，和大部分的强度可以占预共振与更深的UV跃迁在-165 nm。酰胺IF带在D20中占主导地位，这与-* 激发态的主要畸变坐标是CN肽键的拉伸的建议一致。酰胺II的强度与200-和192-nm的激发报告了几种蛋白质。以前报道的负线性相关与-螺旋含量（由于拉曼减色在-螺旋）被发现不适用于蛋白质与高β-折叠含量时，激发波长为200 nm。这些蛋白质的强度要高得多，这归因于β-结构的ir-r* 吸收的红移。与螺旋含量的线性相关性被发现为192 nm的激发，这对应于一个等吸光点的/3-片和随机线圈的吸收带。特征酰胺II拉曼截面推导出螺旋，/3-片，和随机线圈元素，并用于todermining二级结构和/3-嘌呤硫堇，通过使用酰胺II强度与200-和192-nm激发。这一结果与先前基于非共振拉曼光谱中酰胺I带去卷积的测定结果一致，酰胺键是所有蛋白质和多肽的基本结构成分。酰胺间氢键的差异是自然界中蛋白质结构多样性的基础（Creighton，1983）。这种氢键稳定了有序的（二级）结构（例如，β-螺旋和β-折叠），其中相邻酰胺的接近和取向导致显著的偶极相互作用（Creighton，1983）。这种相互作用会影响几种规格-
Department of Chemistry, Princeton University, Princeton, New Jersey 08544 Received September 9, 1986; Revised Manuscript Received December 12, 1986 abstract: Raman intensities obtained with UV laser excitation at 223, 218, 204, 200, and 192 nm are reported for the amide I, II, III, and IF bands of random-coil polylysine. The excitation profiles show enhancement via the-* electronic transition, at~ 190 nm. Enhancement for amide I is weak, however, and most of the intensity can be accounted for by preresonance with a deeper UV transition at—165 nm. The amide IF band dominates the spectrum in D20, consistent with thesuggestion that the main distortion coordinate in the-* excited state is the stretching of the CN peptide bond. Amide II intensities with 200-and 192-nm excitation are reported for several proteins. The previously reported negative linear correlation with-helix content (due to Raman hypochromism in the-helices) is found notto apply to proteins with high/3-sheet content when the excitation wavelength is 200 nm. Much higher intensities are seen for these proteins and are attributed to a red shift of the ir-r* absorption for the/3-structure. A linear correlation with-helix content is found for excitation of 192 nm, which corresponds to an isosbestic point of the/3-sheet and random-coil absorption bands. Characteristic amide II Raman cross sections are derived for-helical,/3-sheet, and random-coil elements and are used todetermine secondary structure for and/3-purothionin, by use of amide II intensities with 200-and 192-nm excitation. The results are in good agreement with a previous determination based on amide I band deconvolution in off-resonance Raman spectra.The amide linkage is the fundamental structural component of all proteins and polypeptides. Differences in inter-amide hydrogen bonding are the basis for the diversity of protein structure exhibited in nature (Creighton, 1983). This H bonding stabilizes well-ordered (secondary) structures (eg,-helix and/3-sheet) where the proximity and orientation of adjacent amides leadto significant dipolar interactions (Creighton, 1983). Such interactions influence several spec-