QUANTITATION OF EPR SPECTRA BY SPECTRAL SIMULATION

通过光谱模拟对 EPR 光谱进行定量

• 批准号: 6307879
• 负责人: NEIL HOGG
• 金额: $ 1.13万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2001-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6307879
• 关键词: bioengineering /biomedical engineering; biomedical resource; computers; technology /technique

Electron paramagnetic resonance (EPR) spin-trapping has been extensively used to detect the formation of transient free radicals in biological and chemical systems. The technique uses a spin-trap that reacts with the free radical to form a persistent spin-adduct, which can be detected directly by EPR. In many cases, radical identification can be accomplished as the spin-adduct of a particular radical has unique spectral features. Spin-trapping has generally been used in a qualitative manner as the spin-adducts are usually too low in concentration and/or too unstable to allow accurate quantification. A good signal to noise ratio is essential for accurate quantification as the EPR spectrum has to be integrated twice in order to derive the concentration of free radical in the sample. We have developed a methodology whereby spectra with poor signal to noise can be quantified. This method uses a spectral simulation to generate a noise free representation of the original spectrum, which can then be quantitatively analyzed by integration. The concentration of individual spin adducts in complex mixtures can be determined. In addition the kinetics of radical production can be analyzed, as signal averaging need not be employed. This approach has been used to determine the kinetics of superoxide formation from xanthine/xanthine oxidase and nitric oxide synthase.

电子顺磁共振（EPR）自旋捕获已经被 广泛用于检测瞬态自由基的形成， 生物和化学系统。 该技术使用了一个自旋阱， 与自由基反应形成持久的自旋加合物， 可以直接用EPR检测。 在许多情况下，激进的 鉴定可以作为特定的化合物的自旋加合物来完成。 自由基具有独特的光谱特征。 自旋捕获通常具有 由于自旋加合物通常也是以定性的方式使用的， 浓度低和/或太不稳定而不能进行准确的 量化 良好的信噪比对于 由于EPR光谱必须积分两次，因此必须进行精确定量 以导出样品中自由基的浓度。 我们已经开发了一种方法，通过该方法， 噪声可以量化。 该方法使用光谱模拟， 生成原始频谱的无噪声表示， 可以通过积分进行定量分析。 浓度 在复杂的混合物中的单个自旋加合物的量可以被确定。 在 此外，可以分析自由基产生的动力学，作为信号 不需要采用平均。 这种方法已被用于 确定由黄嘌呤/黄嘌呤形成超氧化物的动力学 氧化酶和一氧化氮合酶。