Multidimensional Vibrational Circular Dichroism Apparatus Equipped with Quantum Cascade Laser and Its Use for Investigating Some Peptide Systems Containing d-Amino Acids.
Multidimensional Vibrational Circular Dichroism Apparatus Equipped with Quantum Cascade Laser and Its Use for Investigating Some Peptide Systems Containing d-Amino Acids.
复制标题
配备量子级联激光器的多维振动圆二色性装置及其在研究某些含有 d-氨基酸的肽系统中的用途。
作者：
Hisako Sato;Masaru Shimizu;Keisuke Watanabe;J. Yoshida;I. Kawamura;J. Koshoubu
我们开发了一种具有位置坐标的多维振动圆二向色性系统，使得使用自动工作台在x和y方向上移动成为可能。采用量子级联激光器(QCL)作为光源，实现高强度窄聚焦。QCL在1500-1740厘米-1的波数范围内发射光，该吸收带被分配给酰胺I和II的伸缩振动。对含酰胺基团的样品分析了仪器的操作。测定了甘氨酸-L-亮氨酸或甘氨酸-d-亮氨酸的水溶液，由于水介质的背景吸光度高达3.5.光谱以1.0 cm-1步长扫描记录。在每个波数下进行测量所需的时间不超过1个S，光学对极之间保持镜像关系。在1580厘米~(-1)附近有一个清晰的谱峰归属于酰胺II。在含有相同化合物的KBr小丸的情况下，观察到了归属于酰胺I和II的峰。对于二维构图，研究了含有两个氨基酸结构域(或L-丙氨酸和d-丝氨酸)的KBr小丸。在空间间隔2.5 mm的二维排列下，得到了颗粒内各组分的分布。
We developed a multidimensional vibrational circular dichroism system with a positional coordinate, making it possible to move in both x- and y-directions using an automatic stage. Quantum cascade laser (QCL) was used as a light source to achieve high intensity and narrow focusing. The QCL emitted light in the wavenumber range of 1500-1740 cm-1, which encompassed absorption bands assigned to the stretching vibrations of amides I and II. The operation of the instrument was analyzed for samples containing amide groups. An aqueous solution of Gly-l-Leu or Gly-d-Leu was measured under the background absorbance as high as 3.5 due to the water medium. The spectra were recorded by scanning at 1.0 cm-1 steps. The time required for performing measurement at each wavenumber was less than 1 s. The mirror-image relation was maintained between the optical antipodes. A peak assigned to amide II appeared clearly at around 1580 cm-1. In the case of KBr pellets containing the same compounds, peaks assigned to amide I and II were observed. For two-dimensional pattering, a KBr pellet comprising two domains of amino acids (or l-Ala and d-Ser) was investigated. The distribution of each component within the pellet was obtained under the two-dimensional alignment at the spatial interval of 2.5 mm.