College of Engineering and Technology, Southwest University, Chongqing 400716, China; Research Center of Applied Physics, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
Research Center of Applied Physics, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing 400714, China; Chongqing Engineering Research Center of High-Resolution and Three-Dimensional Dynamic Imaging Technology, Chongqing 400714, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Jun 5;254:119611. doi: 10.1016/j.saa.2021.119611. Epub 2021 Feb 23.
The application of terahertz (THz)-based techniques in biomolecule study is very promising but still in its infancy. In the present work, we employed THz time-domain spectroscopy (THz-TDS) and THz time-domain attenuated total reflection (THz-TD-ATR) spectroscopy to investigate the properties of tyrosine (Tyr) enantiomers (L- and D-Tyr) and racemate (DL-Tyr) in solid state and aqueous solutions, respectively. THz absorption spectra of solid L- and D-Tyr show similar absorption spectra with peaks at 0.95, 1.92, 2.06 and 2.60 THz, which are obviously different from the spectrum of DL-Tyr with peaks at 1.5, 2.15 and 2.40 THz. In contrast, although THz absorption spectra of L-Tyr solution and D-Tyr solution are similar and different from the spectrum of DL-Tyr solution, both of them have no observable peaks. Interestingly, it was found that the solution containing equal amounts of L- and D-Tyr has a similar spectrum as that of DL-Tyr solution, as far as the mass concentrations of the two types of solutions are kept the same. On other hand, solid L-, D- and DL-Tyr were also investigated with infrared spectroscopy and Raman spectroscopy, respectively. The results show that the spectra of L- and D-Tyr can be regarded the same but they are slightly different from the spectrum of DL-Tyr. With the aid of principal component analysis (PCA), the difference between L-/D-Tyr and DL-Tyr can be confirmed without any ambiguity. Overall, this work systematically interrogated and evaluated the performance of THz-based techniques in the detection of the chirality of tyrosine.
太赫兹（THz）技术在生物分子研究中的应用具有很大的发展前景，但仍处于起步阶段。本工作采用太赫兹时域光谱（THz-TDS）和太赫兹时域衰减全反射光谱（THz-TD-ATR）技术，分别研究了固体和水溶液中酪氨酸（Tyr）对映体（L-和 D-Tyr）和外消旋体（DL-Tyr）的性质。固态 L-和 D-Tyr 的太赫兹吸收光谱具有相似的吸收谱，在 0.95、1.92、2.06 和 2.60 THz 处有吸收峰，与在 1.5、2.15 和 2.40 THz 处有吸收峰的 DL-Tyr 光谱明显不同。相比之下，尽管 L-Tyr 溶液和 D-Tyr 溶液的太赫兹吸收光谱相似，与 DL-Tyr 溶液的光谱不同，但两者都没有可观测的吸收峰。有趣的是，发现含有等量 L-和 D-Tyr 的溶液与 DL-Tyr 溶液的光谱相似，只要两种溶液的质量浓度保持相同。另一方面，还分别采用红外光谱和拉曼光谱对固态 L-、D-和 DL-Tyr 进行了研究。结果表明，L-和 D-Tyr 的光谱可以视为相同，但与 DL-Tyr 的光谱略有不同。通过主成分分析（PCA），可以明确确认 L-/D-Tyr 与 DL-Tyr 之间的差异。总的来说，本工作系统地研究和评估了太赫兹技术在检测酪氨酸手性方面的性能。
