PHOTOPHYSICS OF FLUORESCENT NON-NATURAL AMINO ACIDS

荧光非天然氨基酸的光物理学

• 批准号: 8362576
• 负责人: FENG GAI
• 金额: $ 0.33万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362576
• 关键词: Amino Acids; Amyloid fibers; Binding; Dehydration; Energy Transfer; Environment; Environmental Risk Factor; Fluorescence; Fluorescent Probes; Frequencies; Funding; Grant; Hydration status; Hydrogen Bonding; Individual; Laboratories; National Center for Research Resources; Optics; Peptides; Phenylalanine; Principal Investigator; Process; Property; Protein Dynamics; Proteins; Research; Research Infrastructure; Resources; Solvents; Source; Stretching; Structure; Time; Tryptophan; Tyrosine; United States National Institutes of Health; Water; cost; membrane model; physical property; protein structure; quantum

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Recently, p-cyanophenylalanine (PheCN) has emerged as a useful spectroscopic probe of protein structure and dynamics. For example, its CN stretching frequency is sensitive to environment and thus has been used to probe the orientation and hydration status of individual sidechains of a peptide that is bound to model membranes , as well as the structure of amyloid fibers. In addition, the fluorescence quantum yield of PheCN in water is about five times larger than that of phenylalanine and decreases upon dehydration, making it an attractive fluorescent probe of protein conformational changes. What is more, its utility as a spectroscopic probe is further increased by its ability to excite tryptophan (Trp) fluorescence via the mechanism of fluorescence energy transfer (FRET). Finally, and perhaps most importantly, the major advantage of using PheCN in protein conformational studies is that as a non-natural amino acid, it minimally perturbs the physical properties of the native protein in question because of its small size, especially when it replaces either a Phe or Tyr (tyrosine) residue in the native sequence. While previous studies have established the utility of PheCN as a valuable fluorescent probe, many details of its photophysics are not known, which, in many cases, limits its application to a qualitative context. Herein, we propose to investigate the fluorescence lifetime and quantum yield of PheCN in a variety of solvents, attempting to understand how environmental factors, such as hydrogen bonding and polarity, determine its fluorescence properties

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 最近，对氰基苯丙氨酸（PheCN）已成为蛋白质结构和动力学的有用光谱探针。例如，其 CN 拉伸频率对环境敏感，因此已用于探测与模型膜结合的肽的各个侧链的方向和水合状态，以及淀粉样蛋白纤维的结构。此外，PheCN在水中的荧光量子产率大约是苯丙氨酸的五倍，并且在脱水时荧光量子产率降低，使其成为蛋白质构象变化的有吸引力的荧光探针。 更重要的是，它通过荧光能量转移（FRET）机制激发色氨酸（Trp）荧光的能力进一步增强了其作为光谱探针的实用性。最后，也许最重要的是，在蛋白质构象研究中使用 PheCN 的主要优点是，作为一种非天然氨基酸，由于其尺寸小，它对所讨论的天然蛋白质的物理性质的干扰最小，特别是当它取代天然序列中的 Phe 或 Tyr（酪氨酸）残基。 虽然之前的研究已经确定了 PheCN 作为一种有价值的荧光探针的实用性，但其光物理学的许多细节尚不清楚，这在许多情况下限制了其在定性背景下的应用。在此，我们建议研究 PheCN 在各种溶剂中的荧光寿命和量子产率，试图了解氢键和极性等环境因素如何决定其荧光性质