LOW FREQUENCY MODES & THEIR ROLE IN EQUILIBRATION

低频模式

• 批准号: 6281051
• 负责人: C M PHILLIPS
• 金额: $ 0.27万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6281051
• 关键词: biological products; biomedical equipment development; biomedical resource; proteins; technology /technique

Vibrational transitions are sensitive to temperature (frequency shifts and bandwidth changes) so we are developing transient IR methods to study heat transport in proteins and other structures in aqueous solutions. In particular, the IR spectrum of water is modified by heating which breaks hydrogen bonds and the proposed methods can measure changes of ca. 0.02 C. In currently planned experiments the changes in temperature arising from the flow of energy from a heme group is studied. The heating step might also be effected by means of an infrared pulse. Specifically, the system proposed as a test bed for this technology are Mb, Hb and Cyt-C derivatives having different ligands. After optical excitation, the ligand may dissociate. The energy of dissociation can go directly to heating the immediate surroundings but the energy retained as internal vibrational energy is bottlenecked. Some energy may be released or consumed in protein structural changes associated with ligand dissociation. The released thermal energy is used to excite mainly low frequency modes of the surroundings. There are not yet answers to how the energy released at the heme flows through the protein which ultimately heats the surrounding H2O. For example, is the protein measurably isotropic or anisotropic in regard to its thermal diffusivity? Does energy bottleneck in specific global structural regions of the protein? Can we find a quantitative theoretical description of the initially created hot spectra? These questions can be addressed directly by probing the IR spectra of transitions in the H2O and the protein that have known temperature dependence.

振动过渡对温度敏感（频率 偏移和带宽变化），因此我们正在开发瞬态IR 研究蛋白质和其他结构中热传输的方法 水溶液。 特别是，水的IR光谱是 通过加热来修改，该加热打破氢键和提议 方法可以测量CA的变化。 0.02 C.当前计划 实验能量流的温度变化 研究了血红素组。 加热步骤也可能受到影响 通过红外脉冲。 具体而言，该系统建议 该技术的测试床是MB，HB和CYT-C衍生物具有 不同的配体。 光激发后，配体可能 游离。 解离能量可以直接加热 周围环境，但能量保留为内部振动 能量是瓶颈。 某些能量可能会被释放或消耗 蛋白质结构变化与配体解离有关。 这 释放的热能用于激发低频模式 周围的环境。 还没有关于能量如何的答案 在血红素流通过蛋白质的血红素流释放，该蛋白质最终加热 周围的H2O。 例如，是蛋白质可测量的各向同性 还是各向异性关于其热扩散率？ 能量 蛋白质的特定全球结构区域中的瓶颈？ 能 我们找到了最初的定量理论描述 创建了热光谱？ 这些问题可以直接解决 探测H2O中过渡和蛋白质的IR谱 具有已知的温度依赖性。