EXAMINATION OF THE SECONDARY STRUCTURE OF PROTEINS BY DECONVOLVED FTIR SPECTRA
EXAMINATION OF THE SECONDARY STRUCTURE OF PROTEINS BY DECONVOLVED FTIR SPECTRA
复制标题
DOI：
10.1002/bip.360250307
复制
发表时间：
1986-03-01
期刊：
影响因子：
2.9
通讯作者：
SUSI, H
中科院分区：
文献类型：
--
作者：
BYLER, DM;SUSI, H
在氧化氘溶液中，在 1600 至 1700 cm-1 范围内以 2 cm-1 分辨率获得了 21 种球状蛋白的傅里叶变换红外 (FTIR) 光谱。将傅里叶自解卷积应用于所有光谱，表明除酪蛋白外的每种蛋白质的酰胺 I 带均由六到九个成分组成。尽管并非所有蛋白质都在每个特征频率上都表现出成分，但在 11 个明确定义的频率下观察到了这些成分。 124 个单独值与 11 个平均特征频率的均方根 (RMS) 偏差为 1.9 cm-1。观察到的组件被分配给螺旋段、扩展β段、无序段和转角。具有相似结构的段不一定表现出具有相同频率的频带分量。例如，较低频率β结构带可以在大约15cm-1的范围内变化。去卷积光谱的各个分量的相对面积由高斯-牛顿迭代曲线拟合程序确定，该程序假定去卷积分量的高斯带包络。测量的面积用于估计 21 种球状蛋白中每种蛋白的螺旋和 β 结构的百分比。结果与 Levitt 和 Greer 从 X 射线数据得出的值基本一致。 22 个值（通过两种技术测量的 11 种富含 β 的蛋白质的 α 和 β 含量）之间的 RMS 偏差为 2.5 个百分点；最大绝对偏差为4个百分点。
Fourier transform ir (FTIR) spectra of 21 globular proteins have been obtained at 2 cm-1 resolution from 1600 to 1700 cm-1 in deuterium oxide solution. Fourier self-deconvolution was applied to all spectra, revealing that the amide I band of each protein except casein consists of six to nine components. The components are observed at 11 well-defined frequencies, although all proteins do not exhibit components at every characteristic frequency. The root mean square (RMS) deviation of 124 individual values from the 11 average characteristic frequencies is 1.9 cm-1. The observed components are assigned to helical segments, extended beta-segments, unordered segments, and turns. Segments with similar structures do not necessarily exhibit band components with identical frequencies. For instance, the lower frequency beta-structure band can vary within a range of approximately 15 cm-1. The relative areas of the individual components of the deconvolved spectra were determined by a Gauss-Newton, iterative curver-fitting procedure that assumed Gaussian band envelopes for the deconvolved components. The measured areas were used to estimate the percentage of helix and beta-structure for each of 21 globular proteins. The results are in good general agreement with values derived from X-ray data by Levitt and Greer. The RMS deviation between 22 values (alpha- and beta-content of 11 beta-rich proteins measured by both techniques) is 2.5 percentage points; the maximum absolute deviation is 4 percentage points.