Terahertz measurements of protein relaxational dynamics
Terahertz measurements of protein relaxational dynamics
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DOI：
10.1109/jproc.2007.898906
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发表时间：
2007-08-01
影响因子：
20.6
通讯作者：
Markelz, Andrea G.
中科院分区：
文献类型：
--
作者：
Knab, Joseph R.;Chen, Jing-Yin;Markelz, Andrea G.
蛋白质的集体结构振动模式位于太赫兹频率范围内。我们讨论了几种测量方法，探索鸡蛋白色溶菌酶的皮秒动力学，这表明太赫兹时域光谱可以提供独特的见解关键蛋白质动力学。我们发现在临界水化点和临界温度下太赫兹吸光度和折射率都迅速增加。具体来说，我们讨论了水化和温度转变，并建议这些可能是联系在一起的。我们讨论的可能性，太赫兹响应主要是由蛋白质内的侧链的弛豫响应和这些运动的能量势垒是水合依赖。最后，我们表明，简单的简正模计算不再现强水合依赖性，进一步表明共振振动响应是不足以描述太赫兹介电响应。
Collective structural vibrational modes of proteins lay in the terahertz frequency range. We discuss several measurements exploring picosecond dynamics in hen egg white lysozyme suggesting that terahertz time domain spectroscopy can provide unique insight to critical protein dynamics. We find a rapid increase in terahertz absorbance and index at both a critical hydration point and separately a critical temperature. Specifically, we discuss the hydration and temperature transitions and suggest that these are possibly linked. We discuss the possibility that the terahertz response is mainly determined by relaxational response of side chains within the protein and the energy barriers for these motions are hydration dependent. Finally we show that simple normal mode calculations do not reproduce the strong hydration dependence, further suggesting that resonant vibrational response is not sufficient to describe the terahertz dielectric response.