SYNTHETIC FLAVO HEMO PROTEINS

合成黄素血蛋白

• 批准号: 6328042
• 负责人: PETER LESLIE DUTTON
• 金额: $ 0.82万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6328042
• 关键词: biological products; biomedical resource; proteins; technology /technique; biological products; biomedical resource; proteins; technology /technique

We have succeeded in designing and constructing de novo synthetic flavo-hemo-proteins that exhibit light activated intraprotein electron transfer. We use our traditional four-helix bundle framework to covalently link a bromoflavin to an interior cysteine very close to the geometric center of the bundle. In the same bundle, interior histidines a positioned to form a bis-His ligation of added heme toward either end of the bundle interior. We have shown that illumination of the blue flavin absorption band creates an excited state which can extract a pair of electrons from a convenient nitrogenous base donor (such as EDTA) to create a reduced flavin that spontaneously transfers electrons to nearby bis-histidine ligated heme. We are presently using the RLBL nanosecond dye laser to capture the spectra of the excited flavin state, the subsequent reduced flavin, and to provide an initial description of the time course of intraprotein electron transfer from the reduced fla vin to the heme. It is quite possible that there will be a heterogeneity of the time course corresponding to a distribution of flavin/heme distances for different conformations of the redox peptide. We expect a competition between flavin excited state quenching by energy transfer to the heme and electron transfer between the flavin and the heme. We will be flowing the synthetic flavo-hemo-protein plus EDTA solution through a cell to compare the spectra of regions with and without the blue pump pulse. We can easily regenerate our material by exposing the solution to molecular oxygen, which rapidly oxidizes the heme component. In addition, we are investigating the viability of using a tryptophan moiety in this electron transfer scheme. The tryptophan residue will be pumped with the fourth harmonic of the Nd:YAG (266 nm).

我们成功地设计和构建了从头综合 表现出光活化的肾上腺素蛋白电子的Flavo-Hemo蛋白 转移。 我们使用传统的四螺旋捆绑框架 共价将Bromoflavin与非常接近的内部半胱氨酸联系起来 束的几何中心。 在同一捆绑中 组成的一个位置以形成双BI-HIS连接添加的血红素 朝束内部的任一端。 我们已经表明 蓝色黄素吸收带的照明产生了激动的 可以从方便的 氮基供体（例如EDTA），以创建减少黄素 自发将电子传输到附近的BIS-HISTIDINE连接 血红素。 我们目前正在使用RLBL纳米染料激光捕获 激发黄素状态的光谱，随后的降低 黄素，并提供有关时间课程的初始描述 肾上腺素内电子从还原的FLA VIN转移到血红素。 很有可能会有当时的异质性 对应于黄素/血红素距离分布的课程 氧化还原肽的不同构象。 我们希望竞争 在黄素激发态通过能量转移到血红素之间 和电子在黄素和血红素之间的转移。 我们会的 将合成的Flavo-Hemo蛋白和EDTA溶液流过 用和不带蓝色泵的区域的光谱进行比较 脉冲。 我们可以通过暴露解决方案轻松再生我们的材料 到分子氧，它迅速氧化血红素成分。 在 此外，我们正在研究使用色氨酸的生存能力 该电子传输方案中的部分。 色氨酸残留物将 用ND的第四个谐波泵送：Yag（266 nm）。