EFFECTS OF FREE ELECTRON LASER FAR INFRARED RADIATION ON LARGE BIOMOLECULES

这一计划的主要目标是实现前所未有的解决方案 在DNA和其他生物分子的远红外(FIR)传输研究中 利用罗格斯自由电子独特的时间依赖性的物种 激光(FEL)。这项研究计划的最终目标是证明 FIR辐射对生化活性的增强作用。一个重要的 第一步是通过实验确定是否存在定义明确的火灾 生物重要分子中的活跃集体模式，如DNA。 这些模式的自然线宽是否比它们的 频率将被确定。低频、大振幅、集合体 DNA中涉及大量原子的模式被提出为 在允许DNA双螺旋结构转变中的重要作用 这是复制和转录等过程所必需的。至 用傅里叶变换光谱仪对取向薄膜的DATA、FIR研究 显示出宽的吸收带，这些吸收带由于 可能的碱基对和残缺的统计分布 沿螺旋轴的构造周期性。使用光子回波技术 罗格斯大学的自由电子激光将得到显著的改善 DNA的FIR光谱的分辨率。术语“光子回波”指的是 从原子系统自发发射的光脉冲 先前由两个相干光脉冲照射，并在 第二个脉冲之后的时间非常接近于两个脉冲之间的时间 激励脉冲。

The major objective of this program is to achieve unprecedented resolution in far-infrared (FIR) transmission studies of DNA and other biomolecular species utilizing the unique time dependence of the Rutgers' free electron laser (FEL). The ultimate goal of this research program is to demonstrate the enhancement of biochemical activity with FIR radiation. An important first step is to experimentally determine the existence of well defined FIR active collective modes in biologically important molecules such as DNA. Whether the natural line widths of these modes are small compared to their frequencies will be determined. Low frequency, large amplitude, collective modes in DNA involving large numbers of atoms have been proposed to be important in allowing the structural transitions in the DNA double helix that are required for processes such as replication and transcription. To date, FIR studies of oriented films using fourier-transform spectrometers have shown broad absorption bands which are inhomogeneously broadened due to the statistical distribution of the possible base pairs and imperfect structural periodicity along the helix axis. Photon echo techniques using the Rutgers' FEL will be applied to obtain significantly improved resolution for the FIR spectra of DNA. The term "photon echo" denotes the pulse of light which is emitted spontaneously from a system of atoms previously irradiated by two coherent light pulses and is observed at a time after the second pulse very nearly equal to the time between the two excitation pulses.