Terahertz Spectroscopy Tracks Proteolysis by a Joint Analysis of Absorptance and Debye Model
Terahertz Spectroscopy Tracks Proteolysis by a Joint Analysis of Absorptance and Debye Model
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DOI：
10.1016/j.bpj.2020.11.003
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发表时间：
2020-12-15
影响因子：
3.4
通讯作者：
Tonouchi, Masayoshi
中科院分区：
文献类型：
--
作者：
Cao, Can;Serita, Kazunori;Tonouchi, Masayoshi
太赫兹波覆盖了生物大分子分子间和分子内相互作用中的弱相互作用、骨架振动和偶极子旋转的能级范围，在生物分子研究中引起了极大的关注。在这项研究中，我们验证了使用太赫兹时域光谱（THz-TDS）对蛋白质消化进行无损和无标记监测的可行性。酸性蛋白酶胃蛋白酶在最佳pH条件下水解牛血清白蛋白。相应的，对照组实验也通过调节pH值灭活胃蛋白酶。利用小型商用THz-TDS对两个实验进行了1 h的跟踪。一方面计算了反应时间依赖的吸收系数，并完成了直接吸收系数分析。结果表明，从宏观角度关注吸收系数的变化趋势，可以很容易地监测蛋白质水解随时间的变化。另一方面，我们探索了使用Debye模型来分析蛋白质水解过程中溶液的介电性质。Debye分析的结果证明，太赫兹- tds可以在分子水平上详细研究生物大分子溶液的微观动力学。我们的研究通过吸收光谱和德拜分析的结合研究了蛋白质水解的过程，并证明了太赫兹光谱是研究生物分子反应的强大技术，在各种领域具有潜在的应用前景。
Terahertz waves have attracted great attention in biomolecule research because of the fact that they cover the range of energy levels of weak interactions, skeleton vibrations, and dipole rotations during inter- and intramolecular interactions in biomacromolecules. In this study, we validated the feasibility of employing terahertz time-domain spectroscopy (THz-TDS) for the nondestructive and label-free monitoring of protein digestion. The acid protease, pepsin, was used at its optimal pH to hydrolyze bovine serum albumin. Correspondingly, the control group experiment was also conducted by adjusting the pH value to inactivate pepsin. The progress of these two experiments was tracked by a compact commercial THz-TDS for 1 h. On one hand, the reaction-time-dependent absorption coefficient was calculated, and a direct absorption coefficient analysis was completed. The results indicate that protein hydrolysis can be easily monitored over time by focusing on the variation tendency of the absorption coefficient from a macroscopic perspective. On the other hand, we explored the use of the Debye model to analyze the dielectric properties of the solution during protein hydrolysis. The results of the Debye analysis prove that it is possible to investigate in detail the microscopic dynamics of biomacromolecule solutions at the molecular level by THz-TDS. Our research examined the process of protein hydrolysis by a combination of absorption spectra and Debye analysis and demonstrated that terahertz spectroscopy is a powerful technology for the investigation of biomolecular reactions, with potential applications in variety of fields.