THz时域光谱在蛋白质研究中的应用进展

太赫兹时域光谱(THz-TDS)是基于飞秒超快激光技术的远红外波段光谱测量新技术,近年来在生命科学、医学制药、安全检测等不同研究领域中的应用进展迅速.文章结合THz-TDS技术的特点及其在生物分子光谱学研究中的物理基础,介绍了近年来利用THz-TDS技术研究氨基酸、肽和蛋白质的结构、构象、动力学及无标记检测等方面取得的成果和最新进展;总结了不同实验条件下测定的不同氨基酸、同种氨基酸异构体及肽在THz波段的吸收系数和折射率,并对不同实验室测定的结果进行了比较;阐述了THz-TDS技术研究干的、含水的蛋白质粉末以及蛋白质溶液的构象及动力学;介绍了THz-TDS技术在生物素-抗生物素蛋白无标记生物传感中的应用,并初步探讨了该技术在生物分子领域应用中有待解决的问题及发展前景.

Progress in Application of THz-TDS to Protein Study

Terahertz time-domain spectroscopy (THz -TDS) is a newly developed terahertz far infrared spectroscopy based on ultra-fast laser technology. Various applications of THz electromagnetic waves have been investigated by researchers in various fields, including life sciences, pharmaceutical, security detection and etc. THz -TDS has been proven a promising technique in biological and medical applications. Absorption spectrum in the THz range provides rich information about structure and weak interactions of molecules. It is expected that the THz waves can be applied to probing the interactions between antibody and antigen, drug and organism. Combining the characteristic of THz -TDS and its physical foundation in biomolecular spectroscopy, the paper provides a general review of the achievements of and the latest progresses in THz -TDS technology in the study of molecular structure, dynamics and label-free detection of amino acid, polypeptide and protein. Investigating the structure and dynamics of amino acids and polypeptides in low-frequency range is necessary and fundamental for comprehensive understanding of protein function. The absorption coefficients and refractive indices of different amino acids and peptides were summarized, and the results from different research groups were collected. The combination of absorption coefficient and refractive index enables us to discuss rigorously the dynamics of the total dipole moment of protein system. Biological polymers are expected to exhibit broad vibrational spectral features in the THz range corresponding to functionally relevant, global and subglobal collective modes with periods on the picosecond timescale. Some studies focused on the absorption spectrum of hydrated, dehydrated protein powder and solvated protein in an effort to monitor these collective motions. The results indicated that THz -TDS allows rapid characterization of the dynamical transition without label. However, THz technique is still in its infancy compared with other electromagnetic waves. The problem and the prospect of the application of THz -TDS at this stage are also discussed.